I guess from my point of view, the "classic look" would more the Helen Slater version. It looked fine to me. And I don't see the changes as being an improvement. But of course, that's just a matter of opinion.In this particular case, it is a little hard to pin down one costume that you can call the character's "classic look." She has had more different costumes than most other major characters. I don't think this one is particularly dark, to be honest; it certainly doesn't appear as dark as Superman's costume in Man of Steel. And the photo that has been released shows her in fairly subdued light.
The animated version took it to the extreme:
Is that super panty hose she's wearing? I can't imagine her getting into that outfit "super-fast" doing her hair and nails while she's at it.