How can I get user type C# syntax highlighting working again in VS 2012 RC?

Question

Somehow part of my syntax highlighting for C# code has disappeared in the VS 2012 IDE. Uninstalling, rebooting, and reinstalling does nothing, nor does resetting the colors

Answer 1

After trying several of the solutions listed here, I eventually found that my issue was caused by a very large (488000+ characters) string variable. Highlighting was working up to that line, but not after it. Once I reduced the length of the string, highlighting in the rest of the file resumed working normally.