The always stylish 'Mad Men' cast. Photo: Courtesy of AMC

The fashion world continues to go mad for "Mad Men."

In honor of the debut of the limited edition "Mad Men" suit, Brooks Brothers converted the fifth floor of its Madison Avenue store in Midtown Manhattan Tuesday to a classically masculine bar, complete with "patrons" (mannequins) clad in outfits borrowed from the show's wardrobe.

Martinis, Manhattans and merriment were the order of the evening, though it was not quite as boisterous as a Sterling Cooper office party.

The show's costume designer Janie Bryant, dressed in a modern sequined dress from Jovanni and a Dolce & Gabbana tailored jacket, shared some of her secrets about our favorite characters with StyleList.

StyleList: What's the style of Don Draper (played by Jon Hamm)?

Bryant: For me, he's always very masculine, very minimal in his color palette with dark browns and grays -- always very masculine tones. Even if he wears a Glen plaid, it will be in the grays.

StyleList: In Rome, Don Draper wore a powder blue jacket -- it was as if a whole new day had dawned with Don Draper going casual.

Bryant: I designed that sports coat for him. They were on vacation. It was their romantic time together and we were seeing this couple in a different situation that we never seen them in. It was about that couple being in a different environment.

Let's talk about Betty (played by January Jones). She has been wearing some interesting dresses, like the one she wore to the Rockefeller fundraiser at her house.

Dress like Don Draper: The 'Mad Men' inspired Brooks Brothers suit. Photo: Courtesy of HWPR

That was one of my favorites. It was silk duchess satin with flocked roses and she was dressing that way because she expected Henry to come. Betty Draper always dresses for a certain part. It's all about creating that façade of perfection. That character is one of my favorites -- I do love Betty Draper. She's a character that is always trying to grow. She's always searching, too.

StyleList: Joan Holloway (Christina Hendricks) was so beautiful in the purple dress she was wearing at Bonwit Teller.

Bryant: I designed that dress for her and I design almost everything for her.

StyleList: Is she hard to fit?

Bryant: She has a very curvaceous figure and I'm very specific with her color palate. When I design pieces, I can really have control over the palette and the design. For that Bonwit Teller scene, we see her in a different place of work; I wanted to see her in something special. It's a little more girly, if you will, and it was ever so subtle.

StyleList also asked the other cast members in attendance to share a secret about the way their characters dress.

Vincent Kartheiser, who plays Pete Campbell, said the noticeable discomfort of his character stems from his own discomfort. "I'm uncomfortable, maybe that just shines through. I think it's unnatural to not be uncomfortable on some level. I'm aware of my own discomfort in certain situations."

Paul Kinsey, played by Michael Gladis, wears mismatched pieces. "He's more bohemian. You assume he's on the way to taking part of the counterculture of the 1960s, even as a dilettante," Gladis told StyleList.

Also wearing separates is Bryan Batt, aka Salvatore Romano. "Janie calls them the 'Sal Separates.' I call them Sal's Garanimals. She mixes and matches my vests and jackets. I'm rarely in just a gray suit. Sal has a little spark to him."