hi there.. i am wanting to know how you can animate material colors in maya? for instance i have a polygon that is colored blue and between frame 0 and frame 50 i have 2 faces selected on that polygon that i want to go from the color blue to the color yellow while the remaining faces of the polygon maintain their blue color. when i try to do this it doesnt work, it just saves the last color to all the frames.

how would i acheive this? thanks for your time...