# RGB

*Red-Green-Blue* (**RGB**) is a color model that represents colors as mixtures of three underlying components (or channels), namely: *red*, *green*, and *blue*. This model describes a color with a sequence of three numbers (typically between 0.0 and 1.0, or between 0 and 255). Each number represents the primary colors' different intensities (or contributions) in determining the final color.

Alone an RGB value has no meaning. A color model defines how the three components relate to a color space. Graphically, a point in a three-dimensional grid or cube represents a color. Each dimension (or axis) corresponds to a different channel. The RGB color model is then a *cubic*, or *Cartesian*, coordinate system of the underlying color space.

For the web, the underlying color space for an RGB value is *sRGB* (Standard RGB), and each RGB component is a number between 0 and 255. Float values are supported.

Note that there are other RGB color spaces, like the *Adobe RGB* color space, that can represent a wider gamut of color than the *sRGB* color space. The coordinates in *sRGB* and *Adobe RGB* are different.

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, `rgb()`

as three separate floats between 0 and 255 (for example, `rgb(46 139.5 87)`

). 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.

RGB is not the only color model that can represent the *sRGB* color space. Cylindrical coordinate systems like the `HSL`

(*hue-saturation-lightness*) or `HWB`

(*hue-whiteness-blackness*) color models are also used to represent a sRGB color on the web.