I recently realized this when there was a heat-wave and I walked through a small patch of trees in the middle of the city. The shadows of buildings were pretty

I recently realized this when there was a heat-wave and I walked through a small patch of trees in the middle of the city. The shadows of buildings were pretty light color and walking through them wasn't changing the temperature noticeably. But between the trees almost all of the sky was blocked - so the diffused light wasn't getting there - and the shadow there was much darker and it was significantly colder than every other part of the city. So - shadows can get darker or lighter, even if there's just one light source and it's very far :).