Yeah it's a pretty jarring effect, it bothers me quite a bit which is why I need to pin this down and resolve it somehow. You can see the effect best by looking at the clouds immediately after closing the chest, they are dark clouds at that point, and within a few seconds, they gradually brighten and become white clouds again. Just like what happens at Minecraft sunset or sunrise. It's not just use of a chest, it happens for other things as well, I just used the chest as an example.
I'm similarly glad to know I'm not the only one this is happening to... now if we can just figure out what it is!! I set my "lighting" option from Moody to Bright, but that only lessens the effect, it's still there. So it doesn't seem to be related to lighting setting.