Yeah I noticed just after posting actually that it's navy blue...
That would be a bit more of a problem. It actually looks like it wouldn't be that hard to make, but the officer's cap would also make sense with his detective thing.
Ugh, is Naoto he or she?! It doesn't make any difference for me if I were to cosplay him/her/it, but it's usually nice to know whether to call someone he or she XD
S/he uses masculine speech patterns like 'boku' but normally someone his age would use 'ore', but he could just be being more formal... then there's the shadow selves picture. It could be photoshopped or it could just blatantly be, Naoto's a girl.