These sky maps were incredibly fun to work on, and added a nice painterly touch to the skies in the PC game "Planetside".
I treated all of these like tiny abstract paintings, focusing on good use of color and mood. I created them entirely in painter and only looked at pictures of skies for inspiration and reference.

After adjusting coordinates in max on various sky domes, I was able to paint these entirely in painter at the rate of one every 45 minutes.

The Red one at the top was one of my favorites of the series.
I was trying to capture the feeling that the sky reflected the mood of the battlefield, and that a severe storm was on its way.

3rd one down - became the most widely used and most versatile of the bunch.

4th one down - this one was primarily done with Corel Painters spatula tool.
It was of a sunrise.

5th one down - This one was of a sunset.

And the last of another alien sunrise.