This should be standardized, and rather than have an artificial emulation of the organization's intended arms, we could use the Greek letter abbreviation followed by the official organization name or vice-versa as the standard, with the Greek letters in bold.
Adding colors or shields runs the risk of users thinking that the affiliation is either fake or else thinking it must be about something else.
Other than that, I support this proposal, and think all collegiate and other service or honor societies or pledge societies (e.g., Psi Chi) would want representation by stickers and categories.