How should I paint Prime's gun?

I'm painting Leader Prime chrome silver on his grey areas and it's looking good. Now, how should I do his gun? Accoridng to the original colouring the basic template is all metal, but I was thinking of taking some creative liberties a la Gundam Seed Destiny's Strike Freedom Gundam, ie a gun with more than one colour. It could look like a super-duper power rifle. Should I try this, and if I should, what colours would you suggest on the gun?
It's just that Prime's skeleton and the gun being the same colour, all silver, looks a bit bland.
It's just that Prime's skeleton and the gun being the same colour, all silver, looks a bit bland.