You're doing sometihng wrong. The appearance/style of data is independent of content, unless things like colour convey some kind of meaningful information, in which case that information should be in the document XHTML (ideally in a style="" attribute) and not the common stylesheet.
no, I wanted to load the information from a seperate C# class that is initiated in code behind. It's ok though, I just set the values in code behind (server side) directly to the elements I want effected. Each venue that uses our BookNow pages can specify their own color theme.