Continuing to animate the pattern

I've tried to make the animation pattern turn by using the expression editor and create an expression.

This will allow the pattern to rotate at a slower pace when the animation is being played. After then, I created a lambert and named it as patternShader. Then I assigned the material to the spheres. I've also created a nurbsCircle2 and set it as a driver while the patternShader as driven to allow the nurbsCircle2 to be the control of the colour change in the spheres. For this part, I used nurbsCircle2 Translate Z. It will be moving from the value of 0 to -22 and the colours will change. So after I've set the individual keys, when I started to move the nurbsCircle2, the colours of the sphere will change. 

After then, I created an expression in the expression editor whereby when the animation started, the nurbsCircle2 will move on it's own and leading the colour change. 

At first, I had difficulty on how to make the nurbsCircle2 to move slower to let the colour change of the sphere to last till the end of the animation. So I tried to adjust the expression that I had and this expression works well with my animation.

This is how it looks like from the top view of my animation currently.

http://www.youtube.com/watch?v=vl4SUvtG9G8&feature=youtu.be