When she had blue hair it was blue dresses so now with purple hair the same color co-ordinating rule applies.
On stage to collect her Spotlight Award at the Billboard Awards, Katy Perry dazzled in her lilac sequined gown from Blumarine which she also teamed with deep purple lips.
From Camilla Belle, to Kate Bosworth, and Jennifer Lopez, rich lip shades are so in right now. For a similar rich amethyst purple to Katy, try out MAC's Smoked Purple shade.
Pics from Zimbio