FFXIV has an "invisible option" for costume parts and effects humorously called "Emperor's New XXX".
Ex: So if it's invisible gloves that make your hands look bare, aka no gloves on, it's "Emperor's New Gloves".
Needless to say it allows for a variety of tricks that you can't normally do and allows for various costume combinations, in FFXIV's looks. (So much so that there are sites and blog posts that praise the variety of looks and possible costume combos in that game. All because they added that one option, players were and are able to get VERY creative with it's limited costume engine).
TLDR: An invisible option for effects (and even costume parts) would be fantastic for COH.
+1 from me for this suggestion. 🙂