Although the game offers up a variety of colors already, a strange glitch was recently discovered in Guilty Gear Xrd -SIGN- that allows players to pick a couple of new palettes we’ve never seen in the game before.
These options give characters access to a magnificent gold color scheme, similar to those seen in fellow Arc System Works franchise BlazBlue, as well as one that turns them into a shadowy version of their former selves. Seeing as they occupy the slots of different colors, however, it’s unlikely they were meant to be found in the final game or were even implemented by the developers in the first place.
Source: Shoryuken