Where can I find bright colored or shiny leotards?

dang girl! you sure do go to a lot of costume parties! check e-bay, a local dance store, a gymnastics/ice skating store (especially since both of these sporting events require leotards OR buy a white cloth/cotton leotard (these materials will take on dye) and buy either a tie dye kit of neon colours, or some boxes of RIT dye in neon colours, making it by yourself wouldn't only be a fun activity, there wouldn't be a chance anyone would have your same outfit, and a leotard thats like hot pink could run up to $50. also try goodwill! goodluck! xo