OK. A common beef for fans - more common that capes, I would say - is those comic characters whose outfits look like they are wearing their underwear on the outside, swimtrunks, whatever.
It's anyone whose close-pant area, is a different colour than the leggings of their costume.
Immediate characters come to mind - Superman, Batman, Orion.
Who are the rest? Can we name them all? And can we get pictures?
__________________
"I'm not smart so much as I am not dumb." - Harlan Ellison
The first Wolvie costume, sure. They have at least fixed that.
Though he didn't wear a costume, Silver Surfer was originally drawn with shorts. They must have been worried about having what looks like a naked character.
Captain America doesn't count. His shorts were the same colour as his leggings, so they blend.
Batman is more tolerable, because black and grey colours mesh better. Superman's red and blue, not so well.
__________________
"I'm not smart so much as I am not dumb." - Harlan Ellison
The thing is, for the movies, Batman is in complete black, which is totally practical for him.
Superman and Spider Man - exactly the same from page to screen. Why do we think that is?
__________________
"I'm not smart so much as I am not dumb." - Harlan Ellison