Katy Perry  dished out a double dose of purple in two different looks at promotional appearances for her fragrance, Purr, in Mexico City over the weekend. She showed a whole lot of skin with a daring purple dress for a party on Friday, and yesterday she wore something short and sparkly for an afternoon photo call. The singer headed south to promote her first scent , which is her latest beauty effort after she made a crackly nail polish for OPI . Katy spent Super Bowl  weekend away from the States, but her music ended up being a big part of the evening — her "California Gurls" opened  the highly anticipated post-game episode of Glee , and there's more to come on Tuesday's installment of the series . Katy will have some prime time fun of her own this evening, with her cameo on How I Met Your Mother  finally going to air.