[Soala]

Ok let me clear =P

-Gray is considered as a colour if its clearly different than black
-When I said 3 DIFFERENT colours maximum, I was talking about the palette limit. You can of course use different shades of green if you used green in your sword as a colour.
What is not allowed is to color your sword with like red-blue-green-yellow, because they are all different colours and you'd need to remove one.

If you didn't understand this, then I can't do anything for you o.o