I’ve seen some interesting stories about atmospheric optical effects lately. Here are a couple you might be interested in reading.
NOVA on Public Broadcasting had a good story about mirages and seeing the city of Chicago appear upside down over a cold Lake Michigan (link).
EarthSky also had an interesting article about why the sky appears green when a tornado is nearby (link). Many meteorologists I know link the green color to the presence of hail rather than tornadoes, but the two are often found within the same supercell storm. It’s a color that is very distinctive!