We went to a little science museum in Watertown a few weeks ago. They had a little display with some polarized light and filters. Otis wasn’t interested, but I thought it was pretty cool so I recreated it at home.
I took the glass pane out of a picture frame and put a bunch of overlapping pieces of clear tape on it. Then I made my computer monitor all white and turned up the brightness. I held the tape-y pane up between the (polarized) light from the monitor and a polarizing filter for my camera and took some pictures. Rotating the filter made the colors go crazy!