'''exemples :'''
*Heroquest : the Background tiles are also in 3 colours. Yet there is a really poor use of the colour used for the mask.
*Head over Heels : probably... yet the colours are better betterly used than in Heroquest. If you look carefully, there are 2 kind of "background" elements... **Real non-masked Background (floor, walls) which use the full 4 colours, **and masked elements such as... Doors, platforms... which are 3 colours only.
===Rasters===