Color name codes, or hex color codes, work to tell the computer which combinations of red light, green light and blue light to display on the computer screen. A hex code has six digits, comprised of three two-digit number and letter combinations that represent red, green and blue, respectively. Each two-digit number or letter combination represents a level of each color on a scale that goes from the numbers zero to nine, then from the letters “A” to “F.”
In hex color codes, a value of zero is the lowest color saturation and a value of “F” is the highest. For instance, the hex code #FFFFFF represents white as the brightest possible shade of the three main colors, whereas a hex code of #000000 represents black as the darkest possible shade of all three main colors. Using hex codes, #FF000000 represents pure red and #0000FF represents pure blue. Abbreviated hex codes work the same way as full-length hex codes do, but only have three digits. Each of the three digits represents a pair of identical digits—for example, #0F0 represents #00FF00.
Hex codes derive their name from the hexadecimal number system, which refers to the two-digit system of counting. Through this system, only two digits are able to represent 256 shades of each base color.