Very nice image. The targets are very well registered. They are very beautiful. Congratulations.
The third photo, with tree nebulas, shows that perhaps the atmosphere betrayed you. We can see left red semi-halo in all stars.
I am having similar chroma with my photos. I think it is due to refraction of atmosphere since in my case I have red at left and blue at right side. Normally it can happens near the horizon. With me they are occuring a bit far from horizon also.