Hi Folks
Got this reply from Damian Peach about the colors -
"They are caused by different aerosol sizes/temperatures and compositions in the Saturnian atmosphere. Youll notice the distinct orange/red coloured coloured around the Polar cap. This only turned Red around Nov 2004, and has been intensifying in colour since. Note also the Green coloured band bordering that, and as you mentioned the dark green polar cap"
Dave Gradwell