Lukas Kristjanson wrote...
All of our characters are designed to support who they are in every aspect, and appearance is a huge one. (..) It just isn’t wise to present your characters in costumes that are against type unless you want to reveal that the characters themselves are against type. You're fighting with the audience's assumptions.
Alternatively, putting character in clothes that are "against the type" may well be an attempt to modify the type itself, or create a new one in the first place -- to name just one example if there was no such attempts, we'd be permanently stuck with
all superheroes wearing either nothing but spandex and underwear on the outside, or... heck, what would they wear if someone didn't come up with
that in the first place? At some point there was no safe stereotype to fall back on; the mind boggles.
Innovation is done by challenging the assumptions, or just by disregarding them (since that tends to amount to the same thing for the receiver)
Because arguments can indeed be made that deep in our souls we are each unique and clothes don’t matter, but judgments are made on appearance all the time, good and bad, and this becomes an especially important consideration when you are trying to communicate in a limited medium.
Picking up on this, have you considered what the fact itself that the characters never change their appearance may tell the audience about them?