Originally Posted by
Ascended
And in some countries, pink is still a boy's color.
But the costume should be a visual representation of the character, at least in some ways. Aquaman has fish scales on his shirt and fins on his gloves and boots, which tells us he's got some sort of connection to water and/or bodies of water. It doesn't have to be painfully direct like "Geo-Force has earth powers and is a king, so his costume has to have rocks and a crown" but the costume should still tell us something about the person wearing it. Superman's bright colors tells us he wants to be seen, his lack of a mask and gloves tell us he's open and honest, his cape tells us that he'll look really cool in dynamic physical poses, like flying and leaping.
I mean, if you see a dude on the street wearing a leather jacket and Metallica t-shirt, you know something about this person. Superhero costumes should do the same thing. It's a visual medium, it works best when the visuals compliment and reinforce the writing.