32-bit color

32-bit color, in a RGB color space, is a color depth that can theoretically allow for up to 4,294,967,296 unique colors. However, it is typically split into four sets of 8-bit values for 256 levels per RGBA channel (red, green, blue, and alpha). The three 8-bit RGB values deliver 16,777,216 unique colors, the same as 24-bit color, but with the addition of 256 levels of transparency defined by the alpha channel. Apple Computer first introduced this colorspace to the Macintosh II series in May 1989 through 32-Bit QuickDraw.