Color depth

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 facilitates 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 (Color Graphics Adapter) displays.
• 4-bit (2⁴ or 16 colors) - EGA (Enhanced Graphics Adapter) displays.
• 8-bit (2⁸ or 256 colors) - VGA (Video Graphics Array) displays.
• 16-bit (2¹⁶ or 65,536 colors) - XGA (eXtended Graphics Array) displays.
• 24-bit (2²⁴ or 16,777,216 colors) - SVGA (Super Video Graphics Array) 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)

Chroma subsampling, Color, Color palette, Color terms, Dithering, High color, Monochrome