This was taken in March 2006 by iceman
http://www.iceinspace.com.au/forum/a...se.php?a=10553
And this is from last week by big-blue
http://www.iceinspace.com.au/forum/a...e.php?a=229124
Advancements in imaging tech and postprocessing aside, the balance of the colors shows a mighty difference.
It's
assumed the colour change comes with altitude. The taller the storm cloud grows, the more ultraviolet light can interact with the chemicals and change their colour.