Billie Eilish reveals her trademark hair is actually a wig. Picture ... The 'Bad Guy' singer posted the revelatory clip when debuting her bleach blonde hair on Instagram, breaking the record ...

And Billie Eilish confessed that her new platinum blonde hair was actually hidden underneath a wig for two months as ... took to TikTok for a quick clip where she revealed her expertly crafted ...

Billie Eilish just debuted platinum blonde ... Billie's hair was its standard black and green at the Grammys on March 14...meaning that the World's a Little Blurry subject was rocking a wig ...