Depends on your look and what you are going for. If you are looking or huistorical authenticity, then grey>navy>black. Of course, there were no double zips, or even zip, hoodies until fairly recently (70's I believe) so that may be a non-factor. Otherwise, grey is the most versatile, while navy is the most difficult to coordinate with (darker) jeans. It can be done, but things really depend on the undertones of the hoodie and the jeans, and this can be tricky. If you don't do it right, it can just look dumb. For example, I have navy "the Cast" hoodie which has some purple undertones which matches well with true blue color of my worn in, broken down RRDS. It does not go with my worn in APC's, which themselves have a purplish cast. FWIW, I have been considering the same hoodie (actually, I've been considering the heavier, classic version), and would probably go with the heather grey.