variations
different colour models:
- HSI, CMYK, CIE
- used for different purposes
screen depth
- number of bits used per pixel
- 24 = 8 bits per colour (RGB) = 16 million colours
- 32 as above, also ‘alpha channel’ (transparency)
- 16 = 5 bits per colour = ‘thousands of colours’
- 8 too few to split, need designed palettes