The monochrome GB games could be recolored to your pleasure, or you could choose some default palette like in the GBC/A
Alternatively there were those specially enhanced superGB games, which brought their own coloring data in the cart,and also a border with graphics. Only game I remember like this is Donkey Kong.
The Tristar is as big as the SNES AFAIK, and the Tristar64 is a bit smaller. But my memory could bewrong.