The colors of the sky

In the 18th puzzle, the background sky is created using a shader graph. I would like to implement this so that the sky can change not only during the day, but also at sunset and at night.

The color of the sky, excluding clouds, is drawn with a gradation depending on the height, and can be changed from the script, so we have to do is change the specified color over time.

We tried specifying this change using a gradation, but it didn’t change as we expected.

This seems to be because the specified color is at almost the opposite position on the color wheel, so the middle point appears grayish.

The result was a gradation that seemed to bring the two specified colors closer to magenta.

The actual color of the sky is more complex, so we tried to figure out how to express it.