Themable CSS is new to SharePoint 2010 and enables designers to define precisely which Web page elements can be themed using the SharePoint site theme option. Theming in SharePoint 2010 is a two-stage process, involving:
1. Creating a theme in PowerPoint 2007 or 2010.
2. Adapting CSS to inherit theme colors and font-types defined in the PowerPoint theme.
Most of the out-of-the-box CSS files in SharePoint 2010 have already been adapted to work with themes. For instance, many of the styles in the main SharePoint CSS file—corev4.css—are theme friendly. What does a theme-friendly style look like? Basically, a style is adapted so that if no theme is applied to the site then the element to which the style applies defaults to the defined ...