I'm thinking of keeping my black 80%, my screen is yellow but I think it's because of burn in.
To be honest, I missed my delivery by 10 minutes, which meant I had to undergo a 4 hour return trip to collect it today, including running for quite some distance and arriving at the depot dead on 8pm (when they are meant to close). I'm in no rush to be petty about my iPhone.
My iPad 3 actually came with a scuff, but it's never something I noticed day to day, and there's been a few scuffs since then anyway. All I can say is enjoy the ****ing thing, otherwise why did you bother buying one!