The two photos were cropped and enlarged in PowerPoint and composited together. The blue flash is weak due to underexposure, so I adjusted the brightness so that the blue flash can be clearly displayed. So the colors of the clouds are slightly different in these two consecutive shots.

In autumn and winter, the haze damage is serious in Taiwan, and it is not easy to have a clean sky to form green flash. At sunset on November 3rd, I actually got green flash and blue flash in the cloudy sky! The most special thing is that the sun did not fall into the sea, but into the clouds above the sea. That is to say, the green flash and blue flash this time occurred in a thin piece of sky between two cloud layers, which is really rare. At that time, the altitude of the sun was about 1.3 degrees.
The famous website Atmospheric Optics calls this phenomenon "Cloud-top flash". It was introduced like this: "Do not assume when the horizon is cloudy that a green flash will not be seen. Sometimes a rare cloud-top flash can occur as the sun sinks behind a distant cloud bank. They are not fully understood but might be a type of mock-mirage flash produced by an inversion layer overlaying the clouds. We need more observations and associated weather data to understand them better."