I've had this suggested a couple of times, but there is a huge problem.You could consider creating different stars glooms! So we can have different star systems with white dwarves stars, or red giants!!
The shader only has information relevant to the current frame it's rendering, it cannot store anything in memory inbetween frames, and all the info is passed in by StarMade itself. As I cannot change the source code of StarMade, I just have to do what I can with the information it provides for me.
If I were to generate a number to determine the colour of the star, this number would be randomly generated each frame, meaning that the star would switch colours very rapidly.
I'm terribly sorry, but this is a case I myself cannot solve.