Web Design in a Nutshell, 3rd Edition

RGB Colors in CSS

RGB colors can be specified in style rules by any of the methods listed in Table D-2.

Table D-2. Methods for specifying RGB colors

Method	Syntax	Example
Six-digit hexadecimal.	#RRGGBB	color: #0033FF
Three-digit RGB shorthand. This method may be used when each RGB value is double digits.	#RGB (interpreted as #RRGGBB )	color: #03F (interpreted as color: #0033FF)
Three decimal values.	rgb(n, n, n)	color: rgb(0,51,255)
Three percentage values (calculated as a percentage of 255).	rgb(%, %, %)	color: rgb(0%, 20%, 100%)