Think China red, silky black, luscious gold and ornate embroidery. Yin and yang, dragons and flames.
RiRi went straight to the source for was was literally the biggest look of the evening, tapping a Chinese couturier rather than putting a Western interpretation on Eastern fashion.
Designer Guo Pei created her ensemble: a massive, fur-trimmed, embroidered gold cape that needed three handlers outside New York's Metropolitan Museum of Art and teased to a bold pink lining and strapless pink minidress that remained essentially invisible underneath.
"It's handmade by one Chinese woman," Rihanna told Vogue's Andre Leon Talley on the red carpet. "It took two years to make this."
The singer called it a "miracle" that she was wearing the outfit. "I saw this beautiful piece on the Internet," she said, while researching Chinese couture. And it all came together from there because, well, she's Rihanna.
J.Lo was covered up only by a curvy red Versace dragon that had no choice but to reveal lots of side-butt. Kendall Jenner also pitched in on Team Kardashian with a lot of side-boob exposed in a sparkling, simple green column from the Calvin Klein Collection with a high neck and lace-up sides.
Monae discussed her black-and-white ensemble with Talley, noting, "The great thing is, black and white represents the yin and yang, the opposite forces attracting, so balance in all things." Another great thing? Girlfriend designed her garb with the help of fast-fashion retailer H&M.
Katie Holmes topped off an elegant, mostly backless black Zac Posen gown with a choppy bob and bangs, sparking speculation that she'd gone the way of the wig.
Amal Clooney, Reese Witherspoon, Helen Mirren, Gigi Hadid and Kris Jenner each had her own take on the color red.
"He's part of the new world. He's the future. So proud to have him tonight," designer Olivier Rousteing enthused to Vogue's Talley. The Biebs, his companion, tossed out bon mots along the lines of "great," "cool," "thanks," "yes" and "I'm really honored."
Wonder if anyone told him
Also this year: Madonna did get an invitation.
Check out the photo gallery above for a peek at lots of outfits from the 2015 red carpet at the Metropolitan Museum of Art's Costume Institute Gala.