It depends, I guess.
If a comic is settled in the real world and nowadays, characters have more outfits maybe, and changes them often. It's up to you, as long as the characters are recognizeable.
In my story (fantasy setting), the main characters have like 3 outfits each: the main, more recognizeable one; then a second one I use when I need a change of pace (after a battle, in a period of rest and such); and finally the outfit for different wheather/travel outfit. Also, I thought of the "social status" of every character: a traveller will own only the clothes that can be carried by foot or horse or I dunno; a king or a nobleman can have more.
I try to keep these outfits similar, so the shape of the character isn't altered too much.
Final note: as @AmeTsunami said, you actually have to draw the outfit a lot of time. In my opinion, it's important to find a balance and don't over decorate everything. Keeping only what you need is enough!
...ok I've babbled a lot, as usual 