The Sun is too small...

I personally don't want the sun to be bigger, I just want it to have variable size and be more colourful.

All of the inner plumbing for the sun is setup to allow for variable size, and it would be relatively trivial to allow you to pick any color you want for the sun, but it's been a low priority to get that working. UI dev time is better spent working on front end and game ui than creating a color picker and sun size options.

Note: Because of the way we do lighting the color of the sun actually has no effect on the color of daylight on individual planets. Having a giant red star system would make discerning the difference between a green and blue team very difficult if we did...