And then there was blue hour. Soon after the sun sets and all that vibrant warm colors start to fade away, a completely new mood sets in, of which many call blue hour. Typically when the sun is far below the horizon, indirect sunlight explodes in hues of blue. If you’re looking for very cool tones then this is your time moment. In fact, only a couple of minutes is all you got. Blue hour usually doesn’t stick around for long. Blue wavelengths are significantly shorter than of red wavelengths, the reason why it darks so quickly once you lose sight of the sun. If you’re not quick, it can definitely pass you by but it’s not always a bad thing. What happens when the sun is gone? Stars come out.