A beautiful sunset

This photo was taken by me after the sunset, using my mobile phone Samsung Galaxy J7. These types of images can be taken during "Blue Hour". Read the paragraph below for better understanding.

The blue hour is a period of twilight in the morning and in the evening, during the civil and nautical twilight phases, when the Sun is at a significant depth below the horizon and when the residual, indirect sunlight takes on a predominantly blue shade. On a clear day, blue hour can be a colorful spectacle, with the indirect sunlight tinting the sky yellow, orange, red, and blue. This effect is caused by the relative diffusibility of short blue wavelengths of light versus the longer red wavelengths. During the blue "hour" (typically a period about 20 minutes in length), red light passes straight into space while blue light is scattered in the atmosphere and therefore reaches Earth's surface. Many artists treasure this period because of the quality of the light. Although the blue hour does not have an official definition, the blue color spectrum is most prominent when the sun is between 4 and 8 degrees below the horizon.