This woman is a spy. Those glowing lights would be great for a rave or a Tron cosplay, but I imagine they're a less-than-ideal accoutrement when your goal is stealth.
Weirdly, Scarlet Witch's new uniform is clearly based on the street clothes she happens to be wearing during the events of Age Of Ultron. You know, when she's brainwashed and watches her twin brother die.
"Thank god you didn't dress me like in the comics."
That's the other weird thing: The costumes never get totally redesigned. It's like all our heroes are also extremely brand-conscious. Sam "The Falcon" Wilson goes costume-less for Winter Soldier, but gets a sweet new one in time for Ant-Man ... and then yet another one for Civil War. But none of those costumes get a unique color-scheme or a strong look, because Falcon isn't really an A-list hero -- he's a spin on Captain America's "brand," and his outfit reflects that.
"It's cool; my powers suck anyway."
The common explanation for this is that it justifies creating new toys, but in what world are toy companies shackled by the rules of the film universe? Toy makers can make whatever the hell they want, as evidenced by the childish knick-knacks I keep on my desk, because I have the maturity of a 14 year-old.
This alien burst from the chest of a punk rocker.
The attention to the costume makes sense because a superhero's appearance is the most important part of their character. That's why Iron Man can switch from being hardcore Libertarian to a government stooge, depending on the needs of the story, but his costume will always be red and yellow. That's why Batman can switch from having a strict "no guns, no killing" policy to rocket-launching an entire platoon of henchman between movies, and nobody but the hardcore nerds like me will care as long as he still has pointy ears and a cape. Literally the only similarity between Henry Caville and Christopher Reeve's Superman is their appearance -- I doubt they'd even be able to agree on what movie to watch while they cuddled on the couch.