Well, VF5FS already has plenty of DLC. Not just colors, but there are thousands of items in the game. You can buy DLC per character, or you can buy it for every character in a couple of bundles.
In regards to Playstation characters: The developers of VF5FS don't really do bonus characters for the console versions. They focus on creating deep, balanced original characters for each new VF game.
Just want to say though, with all of the items in VF5FS, you can certainly make some of the characters look like characters from other games. You could easily make Goh Hinogami look like a character from Yakuza 4. He has a very Yakuza-like fighting style as well. :D