color depth

color depth

The number of bits used to hold a screen pixel. Also called "pixel depth" and "bit depth," the color depth is the maximum number of colors that can be displayed. True Color (24-bit color) is required for photorealistic images and video, and modern graphics cards support this bit depth.

Per Pixel or Per Subpixel
The color depth of a screen can be referenced by the number of bits in each subpixel or by the total number of bits per pixel. For example, 8-bit color and 24-bit color can mean the same system. The 8-bits refers to each red, green and blue subpixel, while the 24-bit means all three subpixels. Likewise, 10-bit color (subpixels) and 30-bit color (pixels) are the same. See indexed color and bit depth.

Bits Per Pixel    Total Colors

    4    16  (Standard VGA)
    8    256 (Super VGA, indexed color)
   15    32K (option on earlier cards)
   16    65K (High Color)
   24    16M (True Color)
   32    16M (True Color + alpha channel)
   30     1B (Deep Color)
   36    68B (Deep Color)
   48   260T (Deep Color)