I have 1 question where did Rick get a brown shirt when he wore a white shirt In season 4
I think that has just gotten progressively browner... it is probably the original white shirt. You get dirty in the zombie apocalypse.
They pilfer what they want from houses, buildings, cars etc. I'm sure they've all packed up some clothes like they do with food, medicines, snacks etc
I don't think he would wear the same shirt all the time. But maybe it's the same shirt, but dirty! In the apocalypse, you don't necessarily stay clean. Dried blood turns brown, for example. So maybe, the white shirt turned brown from dried blood?
What do you think?