The 'Right There' hitmaker - who sensationally replaced Cheryl Cole on the show after she had completed just four auditions - likes to make sure her and Paula's outfits "complement" each other before they work together.
She said: "As for Paula and I, we will find out what colour each other's dresses are that day and try to wear things that will complement each other.
"I want to wear dresses that make me feel like a woman, but I add a rock edge to it as well. That's my style and I'm an artist before I am a judge."
Now 33-year-old Nicole - who appears on the musical TV talent show with Simon Cowell and L.A. Reid - admits her look has changed in recent years.
She told People.com: "My style has evolved into being a little more grown up. It's rock and roll inspired, but chic. Glam rock.
"If I wear a lace dress I throw on a lather jacket to toughen things up, or some crazy boots. I like dresses that are sassy, but have clean lines."