Black hole is for dark coloured cars and white diamond is for light coloured cars... But I'm not sure which one to go for on a soft blue!? I want one that will give it a deeper shine. Or any recommendations that will really make it gleam!? This is what soft blue looks like http://s1040.photobucket.com/albums/b404/MatthewMacGillivray/Rufus/?action=view¤t=IMG_1654.jpg#!oZZ49QQcurrentZZhttp%3A%2F%2Fs1040.photobucket.com%2Falbums%2Fb404%2FMatthewMacGillivray%2FRufus%2F%3Faction%3Dview%26current%3D228484_1978873627936_1126014846_32319770_4479759_n.jpg