The first shot shows the sky as we currently have it. The second one involves an experimental change in the sky rendering code which enables gamma correction also for the sky objects, i.e. stars and nebulae.
I am fully aware that some will prefer the darker skies and that probably includes myself too. However, the correct sky colors should be the ones in the second shot - gamma correction is already performed on both ship objects and planets, after all. As you can see, it is possible to have bright nebulae too and the colors are much more vivid. Notice also how stars appear brighter in the second shot. Anyway, since there are quite a few OXPs which change nebulae and those could maybe break or display funny if the sky rendering changes, I think I will hold off committing any code for now. What I will do instead, is post a test build here and let you Windows users take it for a drive and see what you think for yourselves.
Drop the exe in your oolite.app folder (backup original exe first), then edit your .GNUstepDefaults (backup original first) and add this line:
"skycolor-gamma-correct" = YES;
to activate the feature.