What colors would I use for new monsters? I guess if they don't fit into any category I would make them gray by default. But if I have too many gray, making them blue would be cool (or black). Don't have any purple (color used in Dragon Strike for Heroes). It would probably end up being a different shade of one of the "canonical" colors.
I try to match it as closely to the original as possible, but in many cases all we have was a generic piece that was intended to be painted (so gray) or bone white like a prototype (even if it is nowhere near undead).
Yes, brown gets used for (normal size) rats, but I guess as long as it doesn't end up looking like a lump of poop on my board.
