What is the most appropriate diagram for GUI button design?

Specifically, I have numerous buttons that will be changing color based on state information from operator input and input from various subcomponents and sensors. I would like to use UML or some other type of design diagrams to be able to capture the color transition. Some folks have suggested sequence diagrams, but I haven't been able to find any good examples that show how to incorporate this design artifact. I would really like to head in this direction to help developers.

Thanks a ton for feedback and insights.