Unknown color phenomenon

We went to friends for dinner tonight. They live on a small lake, facing west, and the sun was setting. The surface of the lake was multicoloured - I was blown away, so startled was I. Like a rainbow on the water, or an oil slick (it isn't). Maybe it's pollen? Natural oils from plants? My host says "Oh, I see that all the time." Wow.

To add magic to mystery, the Space Station zoomed by just after 10 pm. It was almost as bright as Venus.