GBC Hardware

This page summarises the key specs of the Game Boy Color and its practical hardware capabilities (both officially-supported and documented hacks).

Graphics

Colour space

The colour space available^{1, 2} for the palettes includes a total of 32,768 colours (15-bit RGB, i.e. 5 bits per colour). Of these colours, up to 56 can be displayed on screen at any one time using standard display methods, but colours like black and white are often used in multiple palettes, due to many tiles needing them, so the total number of colours displayed at any one time (without clever coding trickery) is often less than 56 due to the repeated colours.

Palette

The limitations³ of the graphics unit’s palettes are as follows:

• Up to 8 four-colour palettes can be attributed to background tiles.
• Up to 8 four-colour palettes can be attributed to sprite tiles (although in practice this is more like 3 colours, as at least one "colour" is always used to indicate transparent pixels).
• Each background tile can use one of its 8 four-colour palettes.
• Each sprite tile can use one of its 8 four-colour palettes.

References

1. “List of video game console palettes” article on Wikipedia – https://en.wikipedia.org/wiki/List_of_video_game_console_palettes#Game_Boy_Color
2. “Pan Docs” documentation by Pan et al. – https://bgb.bircd.org/pandocs.htm#lcdcolorpalettescgbonly
3. “How Graphics worked on the Nintendo Game Boy Color” video by Modern Vintage Gamer – https://www.youtube.com/watch?v=ZEJVOH6Pxkg