Hexadecimal color syntax

The hexadecimal color syntax is a notation for describing an sRGB color using its primary color components (red, green, blue) written as hexadecimal numbers, as well as its transparency. It can be used everywhere a <color> type is allowed.

Syntax

#RGB        // The three-value syntax
#RGBA       // The four-value syntax
#RRGGBB     // The six-value syntax
#RRGGBBAA   // The eight-value syntax

Value

R or RR: The red component of the color, as a case-insensitive hexadecimal number between 0 and ff (255)). If there is only one number, it is duplicated: 1 means 11.
G or GG: The green component of the color, as a case-insensitive hexadecimal number between 0 and ff (255)). If there is only one number, it is duplicated: c means cc.
B or BB: The blue component of the color, as a case-insensitive hexadecimal number between 0 and ff (255)). If there is only one number, it is duplicated: 9 means 99.
A or AA Optional: The alpha component of the color, indicating its transparency, as a case-insensitive hexadecimal number between 0 and ff (255)). If there is only one number, it is duplicated: e means ee. 0 represents a fully transparent color, and ffa fully opaque one.

Note: The syntax is case-insensitive #00ff00 is the same as #00FF00.

Examples

/* Hexadecimal syntax for a fully opaque hot pink */
#f09 <div class="c1"></div>
#F09 <div class="c2"></div>
#ff0099 <div class="c3"></div>
#FF0099 <div class="c4"></div>

div {width: 40px; height: 40px;}
.c1 { background: #f09}
.c2 { background: #F09}
.c3 { background: #ff0099}
.c4 { background: #FF0099}

Specifications

Specification
CSS Color Module Level 4 # hex-notation

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
`hexadecimal_rgb`	1	12	1	3	3.5	1	≤37	18	4	10.1	1	1.0
`alpha_hexadecimal_notation`	62	79	49	No	49	10	62	62	49	47	9.3	8.0

Name	CSS
Version
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Last Updated	2022-04-27T17:24:15Z