Night photographer Ben Canales made this image by stacking together roughly 50 different exposures in order to show all of the star trails across the sky. Regarding the color seen in the stars, Canales writes,
The different colors of the star streaks are from the “temperature” of light that the stars burn at. Just like a candle gives and orange light, and a gas stove burns blue- the stars in our sky shine all different sorts of colored light.
A while back, we featured a video tutorial by Canales on how to photograph the night sky. Give that video a look, find a still lake on a clear night, and you can make one of these photographs yourself!