Alternatively called bit depth, pixel depth, color depth refers to the number of bits per pixel on a computer monitor to represent a specific color. The more bits per pixel, the higher color variety and quality of the monitor. The first graphics cards and monitors supported 1-bit color, which was monochrome (most commonly black and white), for early computers like the Apple Macintosh and Atari ST.

Today, most computers support at least 32-bit color, which allows for up to 16.7 million colors. Windows 7 introduced support for 48-bit color, assuming the computer’s video card supports this color depth.

Evolution of color depth

As technology and available system resources have increased, so has the color depth. Below is a listing of all the different color depths over the history of computers.

  • 1-bit (21 or 2 colors) - Monochrome displays.
  • 2-bit (22 or 4 colors) - CGA displays.
  • 4-bit (24 or 16 colors) - EGA displays.
  • 8-bit (28 or 256 colors) - VGA displays.
  • 16-bit (216 or 65,536 colors) - XGA displays.
  • 24-bit (224 or 16,777,216 colors) - SVGA displays.
  • 32-bit (16,777,216 colors + Alpha channel (232 or 4,294,967,296 color combinations))
  • 48-bit (248 or 281,474,976,710,656 colors)

Color, Color terms

  • What’s the difference between 16-bit, 24-bit, and 32-bit color?
  • How to view or change the screen resolution of a monitor.