Directional color change of a surface in animation

I’m trying to change the color of a surface in an animation in a directional or “wipe” manner, where the surface starts all red, then changes to green from left to right over several frames. I’m a Blender novice and would greatly appreciate any suggestions that steer me in the right direction. Thanks!

wgrover

http://blenderartists.org/forum/showthread.php?t=180592

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Perfect - thanks for your help!