How do I make 2 polygons using the same texture 2 different colors?

[Katakiri]

I wish to change the color of Pit's swords separately to make them 2 different colors so I can vertex them into 2 different weapons. I do this all the time for stages, but with a character I only have one model so I'm a bit stumped. (I'm making Strider Hiryu if that makes anyone wanna help me more)

I've seen this done before with hacks like Dimentio (Making Ness' face 2 different colors) so I know it's possible. I just don't know how to do it. :/

[DrPanda]

To do this you have to edit the UV points on the polygon you want to change.
The only way I know how to do that is to import the UV set into 3dsMax and move them around so it's quite a tedious task

I also think that Mewtwo2000 made a tool for doing this, but I don't know how that works.