There is a photoshop script on Saeed Rahid's site that automates removal of colour cast, it really works, been very pleased with results - and takes one press of the mouse button to run ...
The script is on :
http://focusindepth.com/Focusindepth...epth_home.html
I think it is based on the original one on teh photoshop site, and 'tweaked'