So this on google books says that higher pressure lightens - but I did lay down more paint with less of a fan and instead of 8-1-2 (2 being reducer) I went with 8-1-1. So it may have not been the pressure but the volumn and less reducer allowing the flake to go deeper making it less silvery.

http://books.google.com/books?id=zh...%20pressure%20on%20metallics&f=false

http://s1367.photobucket.com/user/rcarmstrong/library/1953%20Chevy%20Pickup