RGB color

RGB (Red, Green, and Blue), like many of the formats we will look at, is a coloring system that’s been around for decades. It works by defining different values for the red, green, and blue components of a color. For example, a red color might be defined in CSS as a hex (hexadecimal) value, #fe0208:

.redness {
    color: #fe0208;
}

The first two digits are the red value in hexadecimal, the next two are the green, and the last two are the blue.

However, with CSS, that same color can equally be described with an RGB functional notation, where each value can be specified in a range from 0 to 255:

.redness {
    color: rgb(254, 2, 8);
}

Hex and RGB values are the kinds of values you will be used to seeing in graphics applications.