Here you go this should help...
Official Mediterranean Blue Thread -
https://g30.bimmerpost.com/forums/sh....php?t=1356844
Official Carbon Black Thread -
https://g30.bimmerpost.com/forums/sh....php?t=1356924
Personally, I prefer Carbon Black as its a really cool color that you don't see to often and has both the shades of black but also dark blue (almost similar to Imperial Blue) while also showing off the metallic effect of the paint nicely, but Mediterranean is also a nice typical Blue that also looks really good.