I originally made this mod for my own enjoyment but now that I've expanded upon it I feel it can be published. I played around with StarDefs, StarSystemDefs and StarArtDefs and their corresponding DDSs to increase the diversity in the size and color of the stars spawned during the map generation phase.
Since there doesn't seem to be any variable governing the percentage of each type of stars being generated, other than the number of times any default star system is repeated in StarSystemDefs, I've doubled the red & white dwarfs - while all the others have only one instance each. I am naturally open to suggestions to improve upon it.
You can find it on the Nexus. I hope you enjoy.