So my favourite colour is purple so here are some books with it on the cover, mind you half of these are still on my TBR.

 The Iron Daughter by Julie Kagawa

 Across the Universe by Beth Revis

 Evermore by Alyson Noel

Stargazer by Claudia Gray

 Poison Study by Maria V. Snyder

The Crown by Kiera Cass

 Untamed by P.C & Kristin Cast

 Spellbound by Rachel Hawkins

 Winter by Marissa Meyer

 Half-blood by Jennifer L Armentrout