First issue comes from lighting and the lens flares/bright stars from the background. If you wanted a big source of light in the bk you should've matched that in the shoot. As is, you need to dim the bright stars in the bk since the main source is from the right.
You can try downloading Colorista from Red Giant- they have a free version. You get three color wheels, one for highlights, one for mid tones and a third for the blacks. You can push the blacks and mid tones to blue to better match the background. Also your compositing could use some light wrapping.
For a quick fix you may try applying the Photo Filter with a "cool" preset, 30- 40%.
That's the quick and dirty way of it, for in depth grading I would recommend spending time with a colorist and "stealing" the art.
If you're trying to match the color and tone of the background try using Color Finesse.
I dislike the term "correction" as it applies to color since it implies there is a "correct" color, unless you're making colors legal ``for broadcast, really you're tweaking the color to taste. You are color grading.