Did I say that? No. I'm saying it's a poor example. The General Audience won't give a damn about a series that lasted one season.
Being simple doesn't mean it won't be changed. Green Lantern had a simple costume too.
There are very few CBMs in this century have had costumes exactly like the comics. In fact, the only three I can think of is Spider-Man, and even his costume had some small changes (raised webbing, etc). Especially in the past few years, when the industry really started getting good.
On Green Lantern, as you said: Look how that turned out.
There's nothing wrong with adding details, like in Spider-Man's costume, or when the costume doesn't make sense for the story, like Batman Begins, changing significant parts, but if the costume makes perfect sense, why mess up a good thing?
Hellboy, Iron Man. The films that stick to the comics costume do well critically and commercially, and the films that do well despite breaking from the comics costume have specific storyline reasons for changing the costumes, not just "well, a lot of other movies are changing the comics costumes, so why don't we? Y'know, for the heck of it."
The costume means something, it tells a story all by itself. Unless you're telling a different kind of story, or you want your movie to suck, don't change it.
Even on those other mediocre films, who added a whole new color scheme to their costumes? Not Captain America, not Thor, not Hulk, not Batman Begins. Superman Returns did. And X-Men did. And guess what? When X-Men pulled themselves out of the funk of X3, they went back to the comics colors because the costumes tell a good story.