Colour depth indicates the number of bits used for each colour component of a single pixel. It reflects the number of colours the monitor can handle; more bits means more colours, but it also means a larger the data size. Colour depth is especially important when working with graphics, photos, and videos.
| Monitor (according to the number of bits per channel) | Number of colours |
| 4-bit monitor | 4096 |
| 6-bit monitor | 262,144 |
| 8-bit monitor | 16,777,216 |
| 10-bit monitor | 1,073,741,824 |
| 15-bit monitor | 35,184,372,088,832 |