There are numerous factors which will determine the colour in a final image that are not specifically tied into processing where processing is kept simple such as
1. Scope
2. Seeing
3. LP
4. SNR
5. Sensitivety of camera used
although what you say about colour being subjective is also true as per this article
http://www.space.com/scienceastronom..._020625-1.html
however to refer to Greg's statement as cods wallop Dougie, may be a bit harsh IMO
Keep it polite.
