I associate the diff colors with traffic lights: red means "after applying this commit, we STOP running this code..." and green means "...and we START running t

I associate the diff colors with traffic lights: red means "after applying this commit, we STOP running this code..." and green means "...and we START running that code". No value judgement intended, and who doesn't love to see a diff with a ton of red replaced with just a little green? Someone was cleaning house!