Desaturating Camera View

Hi there.
I’m new and not to sure if this is even a possibility. At the moment I have a dude in a 2D world who is helping defend a bunker from a horde of zombies.

There is a camera which is following the dude round using a slightly modified version of the marioFollow camera released with the 4.3 upgrade. What I’m wanting to do is drain the color of the camera when the health of the player gets to 10 or less. I’m not even really sure if this is something that is possible.

I understand that you can change the colors/materials of individual elements… But i’m looking for a more overbearing and temporary change to be applied to the view.

If you’re using Untiy Pro, take a look at the image effects that are included with Unity3D. They apply color changes to pixels, after regular rendering, before they’re displayed on screen. I think the Color Correction Curves image effect will do the trick for you. It has a saturation variable, that you can adjust using its slider, or animate using a script.