/vr/ - Retro Games

So, I'm working on a mod where each enemy appears in monochrome and has a colour associated with them (red, yellow, green, blue). The idea is that when you kill an enemy, you steal their colour and you do more damage against enemies with the same colour.
>Imp, Shotgun Guy, Zombie, Hell Knight - Red
>Demon, Lost Soul, Pain Elemental - Blue
>Revenant, Cacodemon, Chaingunner, Baron of Hell - Green
>Arachnotron, Mancubi - Yellow
>Archvile - Monochrome, changes colour depending on the enemy it revives
>Spectre - Black (can't be stolen, does more damage against the player)
>Spider Demon, Cyberdemon - Monochrome

Any thoughts/opinions on which colours each enemy should be?