Long exposures when it gets dark can pick up amazing colours. We see a bit with the naked eye but as it gets darker our vision fails us. The camera however, will pick up much more using a slow shutter speed to harvest as much light as possible.
My photographer niece Bex, and I spent last weekend at Lake Mahinapua. We managed to beat the snowstorm by leaving Thursday evening instead of Friday morning, but nevertheless we had a deluge and the lake rose dramatically. The jetty completely disappeared and the shrubs along the shore on the bank became islands.
Still, we found plenty to photograph, and I came home with a few treasurers such as this image. Magic!