The RGB color model (which stands for Red, Green, Blue) is what UX designers most commonly work with since it's used by electronic displays. It combines red, green, and blue lights to create more than 16 million colors (16,777,216 to be exact). Note that RGB is a device-dependent color model, meaning different devices will display RGB values differently.

RGB is represented using a combination of 3 numerical values that indicate the intensity of each primary color. Each value typically ranges from 0 to 255, where 0 indicates no intensity of that color and 255 indicates the maximum intensity. The 3 values are often written in the format (R, G, B), such as (255, 0, 0) for pure red, (0, 255, 0) for pure green, and (0, 0, 255) for pure blue.