GNU Image Manipulation Program (GIMP) on GNU/Linux. (1) slight levels adjustment to improve contrast; (2) slight increase in color saturation; (3) scaling from the original at 4,160 x 3,120 to 1,600 x 1,200.

This image was taken 18 minutes after sunset, with the sun about 5 degrees below the western horizon. This colorful display was produced by multiple layers of (mostly) high clouds associated with Tropical Storm Philippe, which at the time was traveling in the Atlantic, about 800 kilometers (500 miles) due north of Puerto Rico. It is not unusual for tropical cyclones to produce brightly-colored sunsets, even when located hundreds of kilometers away, and NOAA's National Weather Service (NWS) has explained that "the outer cirrus shields of tropical cyclones have a knack at producing good sunsets." In the case of Philippe, satellite imaging from GOES-16 shows that the clouds extend even past the island, at least 500 kilometers due south.