I couldn't get my ambient lights to do anything even when I followed the owner's manual. So I looked around the net and found a Focus forum with a good discussion of this problem. I thought I would share the solution here since it is the same for the C-Max. If you can't get your ambient lights to change color no matter what you do, you are not alone. The color palette button will only work when the car is turned on, the headlamps are on, and it is dark enough. This is not stated anywhere I could find in the owner's manual. Apparently older model fords with ambient lights did work no matter the light level, but the C-Max has a sensor. I was about to take mine back to the dealer when I saw the post on the other forum. I thought it might save somebody a trip if I posted the answer here.