Hint: This is not photoshopped. The colors are as you see them. It has something to do with “phreatic eruptions.”
Answer: This is an image taken of a temple in central Honshu in Japan, on the boundaries of the Gifu and Nagano provinces. The structure itself is gray because it is covered in ash from a phreatic eruption of Ontake, a nearby volcano. In a phreatic eruption, ash (rather than lava) is ejected upon the surrounding areas.