Glossary
Color Depth
Also: bit depth · color depth (bit depth)
Color depth is the number of bits used to store each pixel's color. 8-bit holds 256 shades per channel — about 16.7 million colors total; higher depths store more shades, reducing visible banding in gradients.
Reviewed by Chad Solomon · Updated June 2026
Explained
How bit depth is measured
Color depth counts bits per color channel. Standard 8-bit images use 8 bits each for red, green, and blue — 24-bit total, giving 16.7 million colors. Adding an alpha channel makes 32-bit. Professional formats like TIFF support 16 bits per channel for finer gradients.
Explained
Banding and indexed color
Too few colors cause banding — visible steps in smooth gradients like skies. GIF and 8-bit indexed PNG store a palette of at most 256 total colors, which suits flat graphics but bands on photos. Full-color (truecolor) formats avoid this.
Put it to use
Related tools
Questions
Frequently asked
- What is 8-bit color depth?
- 8-bit color depth stores 256 shades per channel. Across red, green, and blue that produces about 16.7 million colors, the standard for JPG, PNG, and WebP.
- Why do gradients look banded?
- Banding appears when an image has too few colors to render a smooth gradient, common in 256-color GIF or indexed PNG. A full-color format fixes it.
Keep reading