Only a visual bug, just mildly annoying.
While raining or snowing, if a player picks up an arrow that was shot by a bow or a crossbow that landed on a block, the rain/snow becomes gray for a split second and turns normal right after.
I attached a video, notice how, when I pick up the arrow, the rain and snow goes black. (sorry mp4 was too big to upload)
Duplicates MC-151275.