I really like your concept and your setting, because of this I made an edit
I overdrew nearly all, the only thing I had no idea about what it is was the gauge in the upper left corner.
1) play with the colors, color management and light/shadows (take a look at the edit and compare, i added you the palette)
2) you can also use some techniques like Antialiasing, it doesn't hurt
3) less colors are good, but you can use more if you get a better effect with it. I used 8, still less enough but a more vibrant impression.
4) you can also play with the positions of the stars to add an additional effect
5) I also overworked the textbox, compare the readability
6) sometime less is more
There are still some rough parts in my edit, but all in all it shows you a direction in which you could go.
