Are Red Giants so damned white and yellow in real life? Wowsz?
The colors are based on an RGB table of black-body radiation @ a paticular temperature from stars, and should be accurate. Star 'color' as given is just the peak output: Sol should technically be a green star, and our eyes are most sensitive in green, which is why light-enhancing apparatus pictures are green). The visible color is 'smeared' across the spectrum with a peak at the nominal color, and this smear averages out to what we see. Most artistic renderings appear to be somewhat imaginative: 'red' stars stars, in fact, all stars, should have an ugly, 'washed out' look. The smearing is less significant at low-frequency colors, where we can't see the infra-red portion, and high-frequencies where we can't see the ultra-violet and the output is less 'smeared.' Thus, we get bluish and reddish stars, but mostly white stars in the middle. The luminosity of blue stars also washes out the color further, making them even less blue. So red, it turns out, is the most similar to the color you expect from the name.
Also, most "red" giants are actually orange or yellow stars by color category (peak output). The term is used as a category to describe a stage in the star's life cycle where its temperature relative to its color takes it to the far upper right corner of the Hertzsprung–Russell diagram, making them reddISH and giant.
In the mod, the intensity of the star in-game is largely controlled by the internal halo, and so the core color is more accurate. It was difficult to color-match the texture to the color, so the inner color is actually MORE boldly colored than it should be, but represents an approximate balance between the lighter and darker portions of the color. The light may be seen in the surface effects is darker and more consistent, and is a somewhat more "pure" version of the true color.
EDIT: The darker red dwarfs is partially due to texture choice. This in turn represents that giants have more convection cells than dwarfs. However, the dwarfs end up a little too dark.
Its cool to see the stars in a closer to accurate sizing!
This will change further as the planets fall into line. Habitable will be smaller, dead are just about right, and giants will grow larger. Indeed, giants will be about the same size as brown dwarves (due to a weird coincidence involving gravity and electron degeneracy). I'm working on this now.
Looking forward to your future work on making map generation a little more sane with the larger stars?
I assume you are looking for more biggies. I will likely have to use another log-transformation so that the giants will show up at all. They are a TINY percentage of total stars, mostly because stars spend very little time in that stage. (subgiants are more common, which is why I added them to the game). Ditto almost everything else. Estimates range broadly, but between 45-80% of all stars are red dwarfs, which would make for boring play. So "sane" is relative. I am opting for sane = play value, which is my general default.
Thank you for the feedback! 
