Chrissy Blair Says Carrie Underwood's Designer Made Freedom 250 Fits For Octagon Girls

It's not just the fighters who are fired up for the UFC's Freedom 250 event -- the Octagon girls are, too -- and a special event requires a special outfit!

TMZ Sports talked to Chrissy Blair earlier this week, just after the 'fits were debuted on social media ... with the longtime Octagon girl revealing she actually helped with the looks.

"We were very much involved and I can't wait to see it come to life. And I think all the sequins and the materials like the velvet and the suede and all that, I think it's going to look really cool on camera at night, too."

A bunch of great fights aside, Freedom 250 celebrates the 250th anniversary of the United States of America ... so the girls' outfits needed to be special, and patriotic, and that required a big-time designer.

"Marina is the designer. She's based in L.A. and her team is amazing. I don't know if I'm allowed to say that she's Carrie Underwood's designer, but she is. She did [UFC] Noche as well. They're incredible."

Chrissy says the process was anything but tedious -- it was great.

"I love it. I'm a girl, so I love dress up. And yeah, I just kind of felt like Barbie going in there, like Americana Barbie. So I'm like, this is great. We have boots that match the outfits and it's all custom. So what's not to love?"

Threads aside, Freedom 250 -- an event more than a year in the making and headlined by Justin Gaethje and Ilia Topuria -- goes down Sunday evening from the South Lawn of the White House ... and Chrissy is pumped.

"There's no way my wildest dreams I would have ever thought that one, I'd be working for the UFC for a decade and two, that I would ever get to work a fight at the White House. So it's only a once-in-a-career event, and I'm super excited!"