The debut of Supergirl's red-and-blue superhero suit was exciting, sure, but what about Kara's (Melissa Benoist) everyday wardrobe? Turns out dressing Supergirl in her daily life is actually much more difficult that designing a suit with a cape.

Supergirl's costume designer Kiersten Ronning creates every look on the CBS show besides Kara's superhero suit (which she helped Oscar winner Colleen Atwood design), whether it's a DEO uniform, Cat Grant's (Calista Flockhart) latest office attire or an alien suit. But her biggest challenge so far is deciding how she could differentiate Kara's wardrobe from her superhero costume to make them two completely different characters.

In the end, it all came down to the classic Clark Kent trope: Give her glasses and make her dress quirky to avoid anyone guessing Kara's secret identity.

"It's really hard to shop for Kara," Ronning tells The Hollywood Reporter. "We try to do a little Clark Kent-ish thing there. It's not stuff that's sold in stores. It's not what's in fashion right now, so that's what's hard — trying to make it cute and still appeal to everyone, but at the same time, it's a little bit quirky."

Ronning explains that Kara's day-to-day wardrobe is more expressive of who she is as a person in comparison to her superhero suit.

"I feel like there's a little something about her that's off and not human, but she's trying to fit in," says Ronning. "But we still want her to be cute and all that. So we try to keep her bright. I really almost never use black on her. There's a lot of black in the DEO, and we're trying to keep that whole CatCo world very bright and happy and fun."

And while Ronning reveals the most difficult costume to make so far has been the Martian Manhunter (David Harewood) alien suit, she's enjoyed educating herself on all the comic book characters she's had to design for the show.

"Some of these underlying comic book characters are so fun to work on," says Ronning. "Not growing up myself knowing a lot about comic books, it's been a lot of fun to learn about them and learn about their characteristics and trying to stay true to that while also putting our own spin on it for this show."

Supergirl airs Mondays at 8 p.m. ET/PT on CBS.