Eilish, who took home an award for 'What Was I Made For?', wore a scholarly Willy Chavarria with a tie she received for her birthday Billie Eilish ... uniform-inspired outfit with thrifted heels.

She famously ditched her signature slime green strands and reemerged as a blonde bombshell just one week ago. And Billie Eilish is clearly still smitten with her new look as she took to Instagram ...

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