Oscar-winning costume designer Colleen Atwood has made a career out of bringing fantasy to life through her lavish creations, but perhaps her most impressive feat is allowing the heroes of “Arrow,” “The Flash” and this fall’s “Supergirl” to fight crime in high style.

Below, Atwood discusses designing the eye-catching ensembles for “Arrow’s” Stephen Amell, “The Flash’s” Grant Gustin and “Supergirl’s” Melissa Benoist.

How do you approach designing a superhero’s look?

Well, in the opportunities I’ve had to do it, I go from a story point, from where the script has put the superhero, and then back into the history of that superhero in the world that [they inhabit], the traditions, and try to come up with something that has a touch of the old, but makes it a fresh kind of superhero.

How much does each individual actor inform their costume’s creation?

The thing with a superhero costume is it’s an incredibly functional, high-functioning costume because of the level of activity that takes place within it. So as I develop the costume and see the actor, I see A, what they look great in, what makes them look super and, B, what the actual costume has to do for them, physically how it has to function. Then I have an overall concept. But in the actual designing of the costume, a lot of it takes place in the first fitting; you meet the person and you realize they know what their action’s going to be by then, and you proceed with the first prototype.

As you say, functionality is just as important as looking good on screen — The Flash’s costume has to be something that Grant can run comfortably in, and the Arrow’s costume is involved in a lot of stunt work, so is it a case of never truly knowing how it will work until the actors put it to the test and dash around in it?

I’ve done a lot of dance costumes and action costumes, so you know the areas of vulnerability in a costume like that. So with my first prototype even, the first time they try it on, I’ve already tried to pre-troubleshoot the issues that come along with that kind of costume before they even have to wear them.

So from the use of stretch materials and tech materials, it gives you some leeway with the costume — even though it’s leather, there’s elements of it that look like leather but are not leather, because they have to stretch for a ways. We use all kinds of technical little things like that.

How many versions do you tend to go through, from the first design all the way through to what actually ends up on the screen?

It’s been different on different projects. Usually, the first prototype tells me enough that by the time I get to the second one, I’m in decent shape and then sometimes, after the prototype is the actual costume, and then all the details. On a superhero, you show all the details ahead of time to the studio and the comic companies and make sure that they’re cool with all the stuff that you’ve changed up a bit from your concept drawing to make the costume work, but that usually happens in the second prototype — it’s agreed upon and then you just go for the costume.

Footwear’s a huge part of these costumes, designing the right kind of shoe that have a cool factor, but that the guys don’t slide around in. Especially for The Flash, he really runs in that costume, so it’s a big deal for him. I took the shoes that he had been training in and built his shoe over them to make it. So it was something he was familiar with and that really worked well for him, and then I had a boot maker I know make — I call them the statue pair — the pair that looks really great standing still but maybe doesn’t work as well running. So usually there’s two or three kinds of footwear, sometimes there’s two or three costumes that are good for different kinds of action.

The costumes’ colors are obviously much more muted on screen than their comic book counterparts, so how many color variations do you generally have to go through to land on the right shade?

Usually, I test a lot of different colors, and in the case of The Flash it was a screen on a background, so I played around with different colors applied to a darker surface to give it light when moved at certain angles, because if you get it too dark you don’t see any detail. So you have to be careful to have some kind of highlight to it or capacity for it to light when it’s in a night situation.

The ’90s “Flash” series featured a very bulky, almost mascot-like costume for John Wesley Shipp, and I know that he’s expressed a lot of envy for Grant’s suit versus what he had to wear. He mentioned that they had to build a cooling unit under his costume back in the day. Fabrics and techniques have obviously improved immeasurably since then, but how do you keep your costumes breathable and comfortable?

For the scene work they do, I made it so you could unzip it really quickly, and so he could just open it in between when he had more than a two minute break, which kept it from being a hotbox.

You mentioned that you liked to add little details and highlights to your costumes that perhaps don’t always show up on screen, but that you know are there — what are your favorite additions on the Flash and Arrow outfits?

I love that the print on [The Flash] suit is actually little bolts of lightning but really it just looks like a texture. I had fun with that, and I changed up the medallion a little bit in the center logo [since] I love graphic art. I’ve always got to play around with those things but it’s quite dangerous, because it’s such an iconic thing you have to be careful not to do too much. So with Flash it was good fun, and the headgear is always tricky and a great challenge to pull off, to make a guy look cool with a bathing cap on. [Laughs.]

Arrow, we really wanted him urban, and sexy, and you could almost wear the costume down the street and it would look cool in today’s world. That was a big goal with Arrow and the way the story was set up with his character.

What were your inspirations for the Supergirl costume? I love that it prioritizes practicality over the general comic book principle of revealing a lot of skin, as is the case with a lot of female costumes.

I feel like there’s a real love for Americana with Supergirl, and I wanted to really embrace that heart of women — there’s enough skin out there in the world, it’s not for everybody and Melissa was just the right person to pull it off. When I read the script I was just really blown away by how strong it was, and I wanted the character to have a strength and presence of self without a bunch of stuff.

Looking back at your career, what has been your favorite costume to create so far? Does anything stand out, or is it like being asked to pick a favorite child?

It’s kind of like picking a favorite kid. You forget what you’ve done and you look back and go, “Oh yeah, I really liked that.” I just did a new “Alice In Wonderland,” the second one, I really like some of the stuff I did for that for Alice and the Red Queen, so I’m excited for those costumes. Supergirl was a fun thing in a totally different way. What I love about my life is the variety of things that I get to do, and you never know what’s going to be next.