G'day Paul, Colour looks pretty good to me. The whole image is remarkably good. You can compare your image with an LRGB one done with a 32"RCOS and STL11000 at
http://home.vicnet.net.au/~tishuios/m8.htm
I was pre occupied with getting the best of some fairly substantial unappealing creamy green star haloes and messed the overall colour up in the process. But when you compare the two you will see that your image leaves nothing to be desired.
best,
Doug