Dominion cards for each mana color:
Red: Militia (direct attack)
Blue: Possession (control)
Black: Graverobber (the dead). Maybe Witch
White: Tournament (knights, etc)
Green:
Woodcutter? (green was all about creatures and natural disasters and stuff - not really a dominion theme...)
Ed
I think this is more appropriate:
Red: Saboteur (weak card, involves randomness, has a lot in common with red's land destruction cards such as Stone Rain)
Blue: Scrying Pool (scry, fateseal, card draw and cares about actions which is comparable to caring about Instants and Sorceries, similar to typical blue cards such as Jace, the Mind Sculptor and Peer Through Depths)
Black: Militia (hand size reduction, does usually the same thing as Mind Rot outside the +$2)
White: Monument (+vp isn't the equivalent of life gain, but close enough, buying Monument is pretty much the same as resolving Ajani's Mantra)
Green: Colony (an expensive card with a huge impact, and it also happens to be green in actuality, comparable to Kalonian Behemoth or pretty much any big green creature)
Artifact: Pirate Ship (it has counters and gives $)