I would seriously argue against The Fifth Element being bad costume design. I'd say just the contrary. It's brilliant.
My story with The Fifth Element goes that I'd seen it loads when younger, and as I got older I thought less of it. Then I suddenly realised one day that it's satire. And I realised how stupid I was. And I realised how awesome it is.
The costume design fits perfectly with that satire/parody. It's playing on the costumes that we've seen in sci-fi to this point, taking them to the extreme, and poking fun. It's great.