Very true. But a predominantly yellow shirt isn't going to clash with say Middlesboro, even with bits of red trim and if the red shorts offered a clash, wear the black ones, same with the socks. 3rd kits are nothing but a money making exercise. It's actually a very simple task for any club to have a second kit that doesn't clash with the main kit. So in our case an away kit with no red, white or black (excepting minimal trim), plain shirt not stripes, light coloured shorts and socks (or dark if home kit has white socks).