I just started to encounter this, and I don't know if this is really a bug or not. Every time I remove a paint color from a piece of gear, and I put an embossing on that gear, it automatically is painted white. Also for some reason certain heroes like centurion for example, give me the option to remove paint colors from pieces of gear entirely from one shoulder but the not other. Again I don't know if that's just part of the design codes, but it just didn't make any sense.