If Sophia Bush and then-boyfriend Austin Nichols went as Katy Perry and Russell Brand this year, it would kinda be in poor taste. But they were still together and going strong in 2010 when this photo was taken. If you want to go as Perry this Halloween (sans Brand), getting the look is easy. The key is a colorful wig (really any color of the rainbow will work) and pair with an equally colorful mini dress.