by bar I just mean the rectangle object that I am moving the mouse over.

so yeah, I would like so when I move the cursor over the rectangle to the right, it will look like it's "filling up" by changing color (just in the area you have moved over so far) as you move the mouse further to the right.

does the code just go in the actions layer? thanks for posting it i will try it out later on when I get back onto my mac