Both the CssClass and the BackColor attributes in the skin have been added to the HTML. The former
ended up as a class attribute on the button, and the latter has been transformed into a style
attribute. The MyButton class in the CSS file gives the button its white text and the inline style determines the background color of the button. If you choose the DarkGrey theme in the drop-down list and then look at the HTML again, you’ll notice it has no class and style attributes, giving the button its default look.