I lack the history with the game to really do
justice, but I'll give my takes. Or at least the cards that come to mind whenever someone mentions a color.
Red is
Lightning Bolt, like just about everyone else.
Blue is
Contradict. Not a great card, but I think of it as pretty well encapsulating the color.
Black is
Read The Bones.
White is
Raise The Alarm.
Green for me is the
Terra Stomper.