CSS (Cascading Style Sheets) is a language for describing the rendering of HTML and XML documents on screen, on paper, in speech, etc. To color elements in a document, it uses color related properties and respective values. This draft describes the properties and values that are proposed for CSS level 3. It includes and extends them from properties and values of CSS level 2.
Status of this documentThis document is a draft of one of the "modules" for the upcoming CSS3 specification. It not only describes the color related properties and values that already exist in CSS1 and CSS2, but also proposes new properties and values for CSS3 as well. The Working Group doesn't expect that all implementations of CSS3 will implement all properties or values. Instead, there will probably be a small number of variants of CSS3, so-called "profiles". For example, it may be that only the profile for 32-bit color user agents will include all of the proposed color related properties and values.
The current draft is the result of the merging of relevant parts of the following Recommendations and Working Drafts, and the addition of some new features.
This document is a working draft of the CSS working group which is part of the style activity (see summary). This is a W3C Last Call Working Draft. This is the second last call for this document, because, in response to comments on the previous draft, sufficient changes were made (see Changes below) as to justify reissuing a last call before advancing the document to candidate recommendation. The working group requests that anyone who made comments on the previous last call draft who believes their comments to still apply to please reiterate their comments on this draft. Last call means that the working group believes that this specification is ready and therefore wishes this to be the last call for comments. If the feedback is positive, the working group plans to submit it for consideration as a W3C Candidate Recommendation. Comments can be sent until the 28th of February, 2003.
Comments on, and discussions of this draft should take place on the (archived) public mailing list www-style@w3.org (see instructions). W3C Members can also send comments directly to the CSS working group.
Patent disclosures relevant to CSS may be found on the Working Group's public patent disclosure page.
To find the latest version of this working draft, please follow the "Latest version" link above, or visit the list of W3C Technical Reports.
ChangesTo assist readers who are familiar with the previous draft of this document, this section outlines the major (non-editorial) changes that were made, and the reasons for making them.
CSS3 is a set of modules, divided up and profiled in order to simplify the specification, and to allow implementors the flexibility of supporting the particular modules appropriate for their implementations.
This module describes CSS properties which allow authors to specify the foreground color and opacity of an element. Additional properties allow specification of the ICC color profile and rendering intent of image content. This module also describes in detail the CSS <color> value type.
2. DependenciesThis CSS3 module depends on the following other CSS3 modules:
The following CSS3 modules depend on this CSS3 module:
3. Color properties 3.1. Foreground color: the 'color' property Name: color Value: <color> | inherit | attr(<identifier>,color) Initial: depends on user agent Applies to: all elements Inherited: yes Percentages: N/A Media: visual Computed value: The computed value for HTML4 keywords, RGB hex values and SVG color keywords is the equivalent six digit hex value. The computed value of the keyword 'transparent' is rgba(0,0,0,0). If the color is specified using the attr() syntax then the computed value is the result of evaluating the attribute's value as a <color>. For all other values, the computed value is the specified value.This property describes the foreground color of an element's text content. In addition it is used to provide a potential indirect value (currentColor) for any other properties that accept color values. If the 'currentColor' keyword is set on the 'color' property itself, it is treated as 'color:inherit' at parse time.
There are different ways to specify lime green:
Example(s):
em { color: lime } /* predefined color name */
em { color: rgb(0,255,0) } /* RGB range 0-255 */
To refer to a 'text' attribute on a body element to set the color:
Example(s):
body { color: attr(text,color); } /* use 'text' attribute */
3.1.1. Gamma correction
For information about gamma issues, please consult the Gamma Tutorial in the PNG specification ([PNG1.0]).
In the computation of gamma correction, UAs displaying on a CRT may assume an ideal CRT and ignore any effects on apparent gamma caused by dithering. That means the minimal handling they need to do on current platforms is:
"Applying gamma" means that each of the three R, G and B must be converted to R'=Rgamma, G'=Ggamma, B'=Bgamma, before being handed to the OS.
This may rapidly be done by building a 256-element lookup table once per browser invocation thus:
for i := 0 to 255 do raw := i / 255.0; corr := pow (raw, gamma); table[i] := trunc (0.5 + corr * 255.0) end
which then avoids any need to do transcendental math per color attribute, far less per pixel.
3.2. Transparency: the 'opacity' propertyOpacity can be thought of conceptually as a postprocessing operation. Conceptually, after the element is rendered into an RGBA offscreen image, the opacity setting specifies how to blend the offscreen rendering into the current composite rendering.
Name: opacity Value: <alphavalue> | inherit Initial: 1 none Applies to: all elements Inherited: no Percentages: N/A Media: visual Computed value: The same as the specified value after clipping the <alphavalue> to the range [0.0,1.0].This property permits the specification of a source color profile other than the default.
Example(s):
/* use the specified profile,
even if the image contains an embedded profile */
IMG { color-profile: url("http://example.com/profiles/eg.icm") }
3.4. The 'rendering-intent' property Name: rendering-intent Value: auto | perceptual | relative-colorimetric | saturation | absolute-colorimetric | inherit Initial: auto Applies to: all elements Inherited: yes Percentages: N/A Media: visual Computed value: specified value
This property permits the specification of a color profile rendering intent other than the default. The behavior of values other than auto and inherit are defined by the International Color Consortium standard [ICC32].
SVG 1.0 introduced the @color-profile at-rule as a method for grouping the color-profile and rendering-intent properties.
The @color-profile rule can be used to specify a color profile description. The general form is:
@color-profile { <color-profile-description> }
where the <color-profile-description> has the form:
descriptor: value; [...] descriptor: value;
Each @color-profile rule specifies a value for every color profile descriptor, either implicitly or explicitly. Those not given explicit values in the rule take the initial value listed with each descriptor in this specification. These descriptors apply solely within the context of the @color-profile rule in which they are defined, and do not apply to document language elements. Thus, there is no notion of which elements the descriptors apply to, or whether the values are inherited by child elements.
The following are the descriptors for a <color-profile-description>:
"local(" + <string> + ")" where <string> is the profile's unique ID as specified by International Color Consortium. (Note: Profile description fields do not represent a profile's unique ID. With current ICC proposals, the profile's unique ID is an MD5-encoded value within the profile header.)
See the description of the 'rendering-intent' property.
4. Color unitsA <color> is either a keyword or a numerical specification.
4.1. HTML4 color keywordsThe list of HTML4 keyword color names is: aqua, black, blue, fuchsia, gray, green, lime, maroon, navy, olive, purple, red, silver, teal, white, and yellow. The color names are case-insensitive.
Color names and sRGB valuesExample(s):
body {color: black; background: white }
h1 { color: maroon }
h2 { color: olive }
4.2. Numerical color values 4.2.1. RGB color values
The RGB color model is used in numerical color specifications. These examples all specify the same color:
Example(s):
em { color: #f00 } /* #rgb */
em { color: #ff0000 } /* #rrggbb */
em { color: rgb(255,0,0) } /* integer range 0 - 255 */
em { color: rgb(100%, 0%, 0%) } /* float range 0.0% - 100.0% */
The format of an RGB value in hexadecimal notation is a '#' immediately followed by either three or six hexadecimal characters. The three-digit RGB notation (#rgb) is converted into six-digit form (#rrggbb) by replicating digits, not by adding zeros. For example, #fb0 expands to #ffbb00. This ensures that white (#ffffff) can be specified with the short notation (#fff) and removes any dependencies on the color depth of the display.
The format of an RGB value in the functional notation is 'rgb(' followed by a comma-separated list of three numerical values (either three integer values or three percentage values) followed by ')'. The integer value 255 corresponds to 100%, and to F or FF in the hexadecimal notation: rgb(255,255,255) = rgb(100%,100%,100%) = #FFF. Whitespace characters are allowed around the numerical values.
All RGB colors are specified in the sRGB color space (see [SRGB]). User agents may vary in the fidelity with which they represent these colors, but using sRGB provides an unambiguous and objectively measurable definition of what the color should be, which can be related to international standards (see [COLORIMETRY]).
Values outside the device gamut should be clipped: the red, green, and blue values must be changed to fall within the range supported by the device. For a typical CRT monitor, whose device gamut is the same as sRGB, the three rules below are equivalent:
Example(s):
em { color: rgb(255,0,0) } /* integer range 0 - 255 */
em { color: rgb(300,0,0) } /* clipped to rgb(255,0,0) */
em { color: rgb(255,-10,0) } /* clipped to rgb(255,0,0) */
em { color: rgb(110%, 0%, 0%) } /* clipped to rgb(100%,0%,0%) */
Other devices, such as printers, have different gamuts to sRGB; some colors outside the 0..255 sRGB range will be representable (inside the device gamut), while other colors inside the 0..255 sRGB range will be outside the device gamut and will thus be clipped.
4.2.2. RGBA color valuesThe RGB color model is extended in this specification to include 'alpha' to allow specification of the opacity of a color. These examples all specify the same color:
Example(s):
em { color: rgb(255,0,0) } /* integer range 0 - 255 */
em { color: rgba(255,0,0,1) /* the same, with explicit opacity of 1 */
em { color: rgb(100%,0%,0%) } /* float range 0.0% - 100.0% */
em { color: rgba(100%,0%,0%,1) } /* the same, with explicit opacity of 1 */
Unlike RGB values, there is no hexadecimal notation for an RGBA value.
The format of an RGBA value in the functional notation is 'rgba(' followed by a comma-separated list of three numerical values (either three integer values or three percentage values), followed by an <alphavalue>, followed by ')'. The integer value 255 corresponds to 100%, rgb(255,255,255,0.8) = rgb(100%,100%,100%,0.8). Whitespace characters are allowed around the numerical values.
These examples specify new effects that are now possible with the new rgba() notation:
Example(s):
p { color: rgba(0,0,255,0.5) } /* semi-transparent solid blue */
p { color: rgba(100%, 50%, 0%, 0.1) } /* very transparent solid orange */
Note. If RGBA values are not supported by a user agent, they should be treated like unrecognized values per the CSS forward compatibility parsing rules. RGBA values must NOT be treated as simply an RGB value with the opacity ignored.
4.2.3. 'transparent' color keywordCSS1 introduced the 'transparent' value for the background-color property. CSS2 allowed border-color to also accept the 'transparent' value. The Open eBook(tm) Publication Structure 1.0.1 [OEB101] extended the 'color' property to also accept the 'transparent' keyword. CSS3 extends the color value to include the 'transparent' keyword to allow its use with all properties that accept a <color> value. This simplifies the definition of those properties in CSS3.
CSS3 adds numerical hue-saturation-lightness (HSL) colors as a complement to numerical RGB colors. It has been observed that RGB colors have the following limitations:
There are several other color schemes possible. Advantages of HSL are that it is symmetrical to lightness and darkness (which is not the case with HSV for example), and it is trivial to convert HSL to RGB.
HSL colors are encoding as a triple (hue, saturation, lightness). Hue is represented as an angle of the color circle (i.e. the rainbow represented in a circle). This angle is so typically measured in degrees that the unit is implicit in CSS; syntactically, only a <number> is given. By definition red=0=360, and the other colors are spread around the circle, so green=120, glue=240, etc. Saturation and lightness are represented as percentages. 100% is full saturation, and 0% is a shade of grey. 0% lightness is black, 100% lightness is white, and 50% lightness is 'normal'.
So for instance:
Example(s):
* { color: hsl(0, 100%, 50%) } /* red */
* { color: hsl(120, 100%, 50%) } /* green */
* { color: hsl(120, 100%, 25%) } /* light green */
* { color: hsl(120, 100%, 75%) } /* dark green */
* { color: hsl(120, 50%, 50%) } /* pastel green, and so on */
The advantage of HSL over RGB is that it is far more intuitive: you can guess at the colors you want, and then tweak. It is also easier to create sets of matching colors (by keeping the hue the same and varying the lightness/darkness, and saturation)
The algorithm to translate HSL to RGB is simple (here expressed in ABC which was used to generate the tables.) In these algorithms, all three values (H, S and L) have been normalized to fractions 0..1:
HOW TO RETURN hsl.to.rgb(h, s, l):
SELECT:
l<=0.5: PUT l*(s+1) IN m2
ELSE: PUT l+s-l*s IN m2
PUT l*2-m2 IN m1
PUT hue.to.rgb(m1, m2, h+1/3) IN r
PUT hue.to.rgb(m1, m2, h ) IN g
PUT hue.to.rgb(m1, m2, h-1/3) IN b
RETURN (r, g, b)
HOW TO RETURN hue.to.rgb(m1, m2, h):
IF h<0: PUT h+1 IN h
IF h>1: PUT h-1 IN h
IF h*6<1: RETURN m1+(m2-m1)*h*6
IF h*2<1: RETURN m2
IF h*3<2: RETURN m1+(m2-m1)*(2/3-h)*6
RETURN m1
4.2.4.1. HSL Examples
Each table below represents one hue. Twelve equally spaced colors (i.e. at 30¡ intervals) have been chosen from the color circle: red, yellow, green, cyan, blue, magenta, with all the intermediate colors (the last is the color between magenta and red).
The X axis of each table represents the saturation (100%, 75%, 50%, 25%, 0%).
The Y axis represents the lightness. 50% is 'normal'.
0¡ Red Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 30¡ Red-Yellow (=Orange) Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 60¡ Yellow Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 90¡ Yellow-Green Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 120¡ Green Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 150¡ Green-Cyan Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 180¡ Cyan Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 210¡ Cyan-Blue Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 240¡ Blue Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 270¡ Blue-Magenta Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 300¡ Magenta Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 330¡ Magenta-Red Saturation 100% 75% 50% 25% 0% 100 88 75 63 50 38 25 13 0 4.2.5. HSLA color valuesJust as the 'rgb()' functional notation has the 'rgba()' alpha counterpart, the 'hsl()' functional notation has the 'hsla()' alpha counterpart. These examples specify the same color:
Example(s):
em { color: hsl(120, 100%, 50%) } /* green */
em { color: hsla(120, 100%, 50%, 1) } /* the same, with explicit opacity of 1 */
The format of an HSLA color value in the functional notation is 'hsla(' followed by the hue in degrees, saturation and lightness as a percentage, and an <alphavalue>, followed by ')'. Whitespace characters are allowed around the numerical values.
These examples specify new effects that are now possible with the new hsla() notation:
Example(s):
p { color: hsla(240, 100%, 50%, 0.5) } /* semi-transparent solid blue */
p { color: hsla(30, 100%, 50%, 0.1) } /* very transparent solid orange */
4.3. SVG color keywords
The table below provides a list of the X11 colors [X11COLORS] supported by popular browsers with the addition of gray/grey variants from SVG 1.0. The resulting list is precisely the same as the SVG 1.0 color keyword names. The two color swatches on the left illustrate setting the background color of a table cell in two ways: The first column uses the named color value, and the second column uses the respective numeric color value.
Named Numeric Color Name Hex RGB Decimal AliceBlue #F0F8FF 240,248,255 AntiqueWhite #FAEBD7 250,235,215 Aqua #00FFFF 0,255,255 Aquamarine #7FFFD4 127,255,212 Azure #F0FFFF 240,255,255 Beige #F5F5DC 245,245,220 Bisque #FFE4C4 255,228,196 Black #000000 0,0,0 BlanchedAlmond #FFEBCD 255,235,205 Blue #0000FF 0,0,255 BlueViolet #8A2BE2 138,43,226 Brown #A52A2A 165,42,42 BurlyWood #DEB887 222,184,135 CadetBlue #5F9EA0 95,158,160 Chartreuse #7FFF00 127,255,0 Chocolate #D2691E 210,105,30 Coral #FF7F50 255,127,80 CornflowerBlue #6495ED 100,149,237 Cornsilk #FFF8DC 255,248,220 Crimson #DC143C 220,20,60 Cyan #00FFFF 0,255,255 DarkBlue #00008B 0,0,139 DarkCyan #008B8B 0,139,139 DarkGoldenrod #B8860B 184,134,11 DarkGray #A9A9A9 169,169,169 DarkGreen #006400 0,100,0 DarkGrey #A9A9A9 169,169,169 DarkKhaki #BDB76B 189,183,107 DarkMagenta #8B008B 139,0,139 DarkOliveGreen #556B2F 85,107,47 DarkOrange #FF8C00 255,140,0 DarkOrchid #9932CC 153,50,204 DarkRed #8B0000 139,0,0 DarkSalmon #E9967A 233,150,122 DarkSeaGreen #8FBC8F 143,188,143 DarkSlateBlue #483D8B 72,61,139 DarkSlateGray #2F4F4F 47,79,79 DarkSlateGrey #2F4F4F 47,79,79 DarkTurquoise #00CED1 0,206,209 DarkViolet #9400D3 148,0,211 DeepPink #FF1493 255,20,147 DeepSkyBlue #00BFFF 0,191,255 DimGray #696969 105,105,105 DimGrey #696969 105,105,105 DodgerBlue #1E90FF 30,144,255 FireBrick #B22222 178,34,34 FloralWhite #FFFAF0 255,250,240 ForestGreen #228B22 34,139,34 Fuchsia #FF00FF 255,0,255 Gainsboro #DCDCDC 220,220,220 GhostWhite #F8F8FF 248,248,255 Gold #FFD700 255,215,0 Goldenrod #DAA520 218,165,32 Gray #808080 128,128,128 Green #008000 0,128,0 GreenYellow #ADFF2F 173,255,47 Grey #808080 128,128,128 Honeydew #F0FFF0 240,255,240 HotPink #FF69B4 255,105,180 IndianRed #CD5C5C 205,92,92 Indigo #4B0082 75,0,130 Ivory #FFFFF0 255,255,240 Khaki #F0E68C 240,230,140 Lavender #E6E6FA 230,230,250 LavenderBlush #FFF0F5 255,240,245 LawnGreen #7CFC00 124,252,0 LemonChiffon #FFFACD 255,250,205 LightBlue #ADD8E6 173,216,230 LightCoral #F08080 240,128,128 LightCyan #E0FFFF 224,255,255 LightGoldenrodYellow #FAFAD2 250,250,210 LightGray #D3D3D3 211,211,211 LightGreen #90EE90 144,238,144 LightGrey #D3D3D3 211,211,211 LightPink #FFB6C1 255,182,193 LightSalmon #FFA07A 255,160,122 LightSeaGreen #20B2AA 32,178,170 LightSkyBlue #87CEFA 135,206,250 LightSlateGray #778899 119,136,153 LightSlateGrey #778899 119,136,153 LightSteelBlue #B0C4DE 176,196,222 LightYellow #FFFFE0 255,255,224 Lime #00FF00 0,255,0 LimeGreen #32CD32 50,205,50 Linen #FAF0E6 250,240,230 Magenta #FF00FF 255,0,255 Maroon #800000 128,0,0 MediumAquamarine #66CDAA 102,205,170 MediumBlue #0000CD 0,0,205 MediumOrchid #BA55D3 186,85,211 MediumPurple #9370DB 147,112,219 MediumSeaGreen #3CB371 60,179,113 MediumSlateBlue #7B68EE 123,104,238 MediumSpringGreen #00FA9A 0,250,154 MediumTurquoise #48D1CC 72,209,204 MediumVioletRed #C71585 199,21,133 MidnightBlue #191970 25,25,112 MintCream #F5FFFA 245,255,250 MistyRose #FFE4E1 255,228,225 Moccasin #FFE4B5 255,228,181 NavajoWhite #FFDEAD 255,222,173 Navy #000080 0,0,128 OldLace #FDF5E6 253,245,230 Olive #808000 128,128,0 OliveDrab #6B8E23 107,142,35 Orange #FFA500 255,165,0 OrangeRed #FF4500 255,69,0 Orchid #DA70D6 218,112,214 PaleGoldenrod #EEE8AA 238,232,170 PaleGreen #98FB98 152,251,152 PaleTurquoise #AFEEEE 175,238,238 PaleVioletRed #DB7093 219,112,147 PapayaWhip #FFEFD5 255,239,213 PeachPuff #FFDAB9 255,218,185 Peru #CD853F 205,133,63 Pink #FFC0CB 255,192,203 Plum #DDA0DD 221,160,221 PowderBlue #B0E0E6 176,224,230 Purple #800080 128,0,128 Red #FF0000 255,0,0 RosyBrown #BC8F8F 188,143,143 RoyalBlue #4169E1 65,105,225 SaddleBrown #8B4513 139,69,19 Salmon #FA8072 250,128,114 SandyBrown #F4A460 244,164,96 SeaGreen #2E8B57 46,139,87 Seashell #FFF5EE 255,245,238 Sienna #A0522D 160,82,45 Silver #C0C0C0 192,192,192 SkyBlue #87CEEB 135,206,235 SlateBlue #6A5ACD 106,90,205 SlateGray #708090 112,128,144 SlateGrey #708090 112,128,144 Snow #FFFAFA 255,250,250 SpringGreen #00FF7F 0,255,127 SteelBlue #4682B4 70,130,180 Tan #D2B48C 210,180,140 Teal #008080 0,128,128 Thistle #D8BFD8 216,191,216 Tomato #FF6347 255,99,71 Turquoise #40E0D0 64,224,208 Violet #EE82EE 238,130,238 Wheat #F5DEB3 245,222,179 White #FFFFFF 255,255,255 WhiteSmoke #F5F5F5 245,245,245 Yellow #FFFF00 255,255,0 YellowGreen #9ACD32 154,205,50 4.4. 'currentColor' color keywordCSS1 and CSS2 defined the initial value of the 'border-color' property to be the value of the 'color' property
but did not define a corresponding keyword. This omission was recognized by SVG, and thus SVG1.0 introduced the 'currentColor' value for the 'fill', 'stroke', 'stop-color', 'flood-color', 'lighting-color' properties. CSS3 extends the color value to include the 'currentColor' keyword to allow its use with all properties that accept a <color> value. This simplifies the definition of those properties in CSS3.
In addition to being able to assign pre-defined color values to text, backgrounds, etc., CSS3, like CSS2, allows authors to specify colors in a manner that integrates them into the user's graphic environment. Style rules that take into account user preferences thus offer the following advantages:
For systems that do not have a corresponding value, the specified value should be mapped to the nearest system attribute, or to a default color. Note that some profiles of CSS may not support System Colors at all.
The following lists additional values for color-related CSS attributes and their general meaning. Any color property can take one of the following names. Although these are case-insensitive, it is recommended that the mixed capitalization shown below be used, to make the names more legible.
Example(s):
For example, to set the foreground and background colors of a paragraph to the same foreground and background colors of the user's window, write the following:
p { color: WindowText; background-color: Window }
Note. The computed value of a System Color keyword value is the keyword itself. In addition, in future CSS specifications, the color property may accept additional System Color values.
4.5.2. CSS3 User preferences for hyperlink colorsMost desktop user agents allow the user to choose the default colors for hyperlinks to be rendered in their various states. The following system colors permit an author to explicitly style their hyperlinks in accordance with those preferences. The color names, though case-insensitive, are presented here in mixed case (camel-case in particular) in order to be consistent with the CSS2 system colors.
Example(s):
For example, to set all links to their default visited and unvisited colors, write the following:
:link {
color: HyperlinkText;
background-color: Hyperlink
}
:visited {
color: VisitedHyperlinkText;
background-color: VisitedHyperlink
}
4.5.3. 'flavor' system color
DEPRECATED EXAMPLE:
:focus {outline: 1px solid flavor}
/* puts an outline around the currently focused element that color
coordinates with the browser accent color if any */
4.6. Notes on using colors
Although colors can add significant amounts of information to document and make them more readable, please consider the W3C Web Content Accessibility Guidelines [WCAG] when including color in your documents.
5. Sample style sheet for HTML 4.0This appendix is informative, not normative.
body {
color: black;
background: white;
color-profile: sRGB;
rendering-intent: auto
}
/* traditional desktop user agent colors for hyperlinks */
:link { color: blue; }
:visited { color: purple; }
/* user preferences for hyperlinks */
:link {
color: HyperlinkText;
background-color: Hyperlink
}
:visited {
color: VisitedHyperlinkText;
background-color: VisitedHyperlink
}
:link:hover,:visited:hover {
color: HoverHyperlinkText;
background-color: HoverHyperlink
}
:link:active,:visited:active {
color: ActiveHyperlinkText;
background-color: ActiveHyperlink
}
img,object {
color-profile: auto;
rendering-intent: auto
}
/* default focus outline */
:focus {
outline: 1px dotted gray;
outline: 1px solid flavor;
}
6. Profiles
Each specification using CSS3 Color must define the subset of CSS3 Color features it allows and excludes, and describe the local meaning of all the components of that subset.
Non normative examples:
CSS3 Color profile Specification HTML4 Accepts HTML4 color keywords'color' property
'opacity' property
'color-profile' property
'rendering-intent' property
@color-profile rule
RGB three digit hex color values and RGB functional notation color values
RGBA color values
HSL and HSLA color values
SVG color keywords
'currentColor' color value
CSS2 UI Colors
CSS3 Hyperlink Colors
'transparent' color value
'flavor' color value
'opacity' property
'color-profile' property
'rendering-intent' property
@color-profile rule
RGBA color values
HSL and HSLA color values
SVG color keywords
'currentColor' color value
CSS2 UI Colors
CSS3 Hyperlink Colors
'transparent' color value
'flavor' color value
'opacity' property
'color-profile' property
'rendering-intent' property
@color-profile rule
RGBA color values
HSL and HSLA color values
SVG color keywords
'currentColor' color value
CSS3 Hyperlink Colors
'flavor' color value
'color-profile' property
'rendering-intent' property
RGBA color values
HSL and HSLA color values
CSS3 Hyperlink Colors
'transparent' color value
'flavor' color value
This specification contains a test suite allowing user agents to verify their basic conformance to the specification. This test suite does not pretend to be exhaustive and does not cover all possible numerical color values. These tests are available [link forthcoming].
8. AcknowledgmentsThanks to Brad Pettit for both writing up color-profiles, and for implementing it. Thanks to Steven Pemberton for his write up on HSL colors. Thanks to feedback from Marc Attinasi, David Baron, Bert Bos, Ian Hickson, Steve Zilles. And thanks to Chris Lilley for being the resident CSS Color expert.
9. References 9.1. NormativeRetroSearch is an open source project built by @garambo | Open a GitHub Issue
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