Hi George,
I think that is a massive improvement on your last effort
well done, better star shape and framing - you have also teased out more of the nebula.
I can't pinpoint your colour issue, there must be something going wrong with programs you use / your work flow - that is all i can suggest.
a give away is the star colours there isn't anything there, carina is rich with red and blue stars see
https://www.flickr.com/photos/803366...ream/lightbox/
have you got a single sub you can post that has come straight off the camera? is there colour there?
Russ