Red Green Blue (RGB) is a color model that represents colors as mixtures of three underlying components (or channels), namely, red, green, and blue. Each color is described by a sequence of three numbers (typically between 0.0 and 1.0, or between 0 and 255) that represent the different intensities (or contributions) of red, green, and blue, in determining the final color.
There are many ways to describe the RGB components of a color. In CSS they can be represented as a single 24-bit integer in hexadecimal notation (for example, #add8e6 is light blue), or in functional notation as three separate 8-bit integers (for example, rgb(46, 139, 87) is sea green). In OpenGL, WebGL, and GLSL the red-green-blue components are fractions (floating-point numbers between 0.0 and 1.0), although in the actual color buffer they are typically stored as 8-bit integers. Graphically, a color can be represented as a point in a three-dimensional grid or cube, where each dimension (or axis) corresponds to a different channel.