She famously ditched her signature slime green strands and reemerged as a blonde bombshell just one week ago. And Billie Eilish is clearly ... to show off her Gucci-only outfit.

Billie Eilish's relationship with Jesse ... with Rutherford sporting Gucci pajamas and fuzzy slippers and Eilish wearing a Gucci silk floor-length nightgown complete with a sleeping mask on ...

"I've always wanted to do this," Eilish said of attending her first Met Gala. "I was just scared and didn't feel comfortable in my skin." Billie Eilish ... from Burberry, Gucci, Louis Vuitton ...