The Girls Aloud star customised the outfit after being called the name by Matt Willis of Busted in 2003.
Roberts told The Guardian: "I've still got it. It's in my wardrobe. I want to get it framed, actually. I'm going to put it where my plaques are."
When her actions were described as 'ballsy', Roberts said: "Well I had to be. What else would I have done? Gone on stage with tear marks? What else?"
Of Louis Walsh's supposed dislike of her when he managed Girls Aloud, Roberts added: "I knew that. I could see that he clearly didn't want me there.
"Don't tell me to smile, seriously. There ain't one inch of a smile in me right now when your eyes are like that, thinking, 'Please God don't let her be in the band'."
Roberts last week premiered her debut solo single 'Beat Of My Drum'.
The singer has said that she would like to be "heavily involved" in the writing of any new Girls Aloud material.
Watch the Nicola Roberts 'Beat Of My Drum' video below: