I'm not saying this with 100% confidence, because I am having issues with the cms page widget, but it doesn't appear that the button settings have effect in the CMS widget (but they do on the forum).
I've rigged it so it is working on my site how I would like. But I don't think it is correctly applying the button color css to the cms widget. On my site it was missing the css necessary to change the color. But since I know what color I want, I have manually added the css so I'm all good.