The Number of colours is calculated as using 2bit depth So we have the following. The phrase colour depth can be used in place of bit depth.
| Colour Depth | Number of Colours | Description |
| 1 | 2 | Black and White |
| 8 | 256 | 8bit |
| 16 | 65,536 | High Colour |
| 24 | 16,777,216 | True Colour |
On a side note, I asked the maths department how to go from the number of colours to the colour depth.
Mr Barnstaple helpfully provided me with this
- Colours = 2Bit Depth
- Bit Depth=log(Colours)/log(2)
Which is I’m sure we will all agree very useful, but it might be easier to memorise the table above 😉
PS if you want the proof here it is
- Take log of both sides
- log 2x = log y
- xlog 2 = log y (log laws)
- x = log y/log 2
Which higher maths cover in unit 3.
