These are the GB games I'd like to receive color patches:
Avenging Spirit: An original platform/beat'em in which you're a ghost capable of possessing enemies with different abilities. Although there is an arcade version with superior visuals (and difficulty), the GB version has some charm.
Jurassic Park Part 2 - The Chaos Continues: It's a good platform game (unlike its predecessor).
Kid Icarus - Of Myths and Monsters
And some homebrew like Deadeus, done with GB Studio before it supported GBC.