Instagram's Eva Chen, after Topshop Unique, London, September 2015.
Two-tone jeans (Eva's are by Edit I think). 
Recreate Eva's look (kind of):
Two-tone jeans (with varying degrees of two-toneness!) — Vila Two-tone skinny jeans, Valentino Two-tone jeans, Blank Denim two tone jeans, Topshop Moto two tone paneled mom jeans, or Simon Miller Hiko Wide leg jeans