Lo-fi retro-GPU styles.

https://github.com/janvancoppenolle/LUT/tree/main/Retro%20GPU%20Conversion

Input = 24-bit RGB
A B C

3-level RGB (27 colours)
A B C

6-bit RGB (64 colours)
A B C

6-level RGB (216 colours = web safe palette)
A B C

3-3-2-bit RGB (256 colours)
A B C

9-bit RGB (512 colours)
A B C