Please provide <plain> </plain> tags that can remove text formatting, so one could remove formatting from class names, for example.
The last beta https://dl.dropboxusercontent.com/u/13064071/plantuml.jarsupports:
skinparam classFontStyle bold
enum BookCategory as "<color:#888888><plain>Enumeration</plain></color>\nBookCategory"
However, very few tests have been done, so please post here if you find issues with this new syntax.