Agreed. I see two areas that need to be considered.
Color gradation. i.e. in this image
the left-most is full red, second full red half green, middle full red full green, half red full green, right-most full green
So you could do a transition in twenty steps but are the intermediate colors acceptable to you?
*As Ralph mentioned, if "click cheating" is a concern, that would need to be addressed somehow too.