Color explanation:

Platinum Bronze = the color facelifted X3 is wearing in official press photos (light golden color).

Space Gray is the color E92 3er Coupe was photographed in.

Mineral Green is a tropical sea like light blue / green color (I named it Petrol Jade sometimes ago).

All the other colors can be found in e.g. E90 3er sedan palette. The best is to visit car configurator on e.g. www.bmwusa.com