I was told this was not possible
I vaguely remember a command (Atleast, pre-V9) that could could get the value of a player's node colour. You'd just need to give the hand on the gun one of those colour changeable textures, and using a script apply it to the hand. And then get rid of the gun holding hand since you don't need it on the model.
Of course I could be wrong. It's been awhile since I've messed with Blockland. (Like, A long time before V9 was out)