© Photo: Getty ImagesThe former Pussycat Dolls singer took the top knot from day to night when she arrived at The X Factor auditions in London, leaving the rest of her tresses down in a poker straight edgy style.
© Photo: Getty ImagesNicole was the epitome of laidback elegance at the One for the Boys Fashion Ball by wearing her smooth locks down in a dramatic side parting.
© Photo: Getty ImagesThe singer was the epitome of elegance with this chic voluminous blow-dry hairstyle.
© Photo: Getty ImagesNicole could have stepped out of old Hollywood when she stepped out with these retro-esque flawless curls.
© Photo: Getty ImagesThe X Factor judge had us reaching for the straighteners with this glossy, poker straight look.
© Photo: Getty ImagesThe singer majorly upped the beauty stakes when she rocked this sideswept curly hairdo as she attended the launch of Cats.
© Photo: Getty ImagesThe Don't Hold Your Breath hitmaker looked effortlessly cool with this slightly undone top knot paired with tumbling tousled waves.
© Photo: Getty ImagesNicole showed off her beauty credentials with smooth and slicked back hairstyle – take note from the star and pair with a statement red lip for ultimate wow factor.
© Photo: Getty ImagesNicole mastered daytime glamour with this large, slightly undone bun, giving us major hair inspiration in the process.
© Photo: Getty ImagesIf you're thinking of going for an ombré colour, take a leaf out of Nicole's book and opt for sleek layers to show off the varying shades.
