Problem with "Material"

I’m doing the tutorial provided by SketchUp on creating dynamic components. I’ve followed the instructions carefully (I think) but when I try to create an on click interaction on colour - I’m using this: SET(“Material”,”red”,”green”,”blue”). But I get the following error: ERROR: Invalid entity to animate: (“Material”). Am I being really stupid and missing something obvious?

Have you checked your smart quotations?

Thank you! I just figured out that was the problem. Was driving me crazy and it was so simple! Thanks for taking the time to respond. Jen