Thanks Mike and Troy,
I don't normally play with white balance Mike but it is set to manual. I did recently adjust it for Mars, but thought I'd put it back

(I raised the blue, maybe I put it back too far?)
Suddenly people are commenting on the muted contrast and yellow cast

I must look back on some old stuff to see if I have changed, or maybe the camera settings, or my monitor calibration may be crook.
The other factor that has been raised as a possible cause is that I have no UV or IR filter on the camera

do you think this will help

Also what role does Gamma play in this, as it is set fairly low as well?