Thanks a lot for the reply!
It's reassuring to hear that baking a light map will maintain the colour. What was happening for me was, when using the light map, I was seeing an increased brightness and shadows at various points along the floor which I expected but the nice warm effect given by the yellow tinged lighting was not as obvious (it was in 3DS). Perhaps it is my eye-sight! I will exaggerate the colour of the light further and see if this helps. If not, I shall attach screen-shots here and explain my process in more detail.
Thanks for the photoshop cheat. I will give this a go and see what kind of results I get as well.
I will try the tips you suggested and update the thread at some point in the next few days. Hopefully, I will get the desired results and be able to post my methods for other people to use! Watch this space