I think it's okay too! Where I live, the weather is really moderate so I guess I always think it's okay as long as the whether is pretty - not white shoes though! (LOL!)
White MC should be used in the warm weather months (especially in NYC). For some reason white MC looks bad in the winter here. If you are in a state that have warm weather all year around its fine
I feel the same way. I wear darker colors this time of year, so the white background doesn't look right. I usually carry my MC with the black background pretty much all year, but retire the white background by mid-September.