I'd like to write an extension for Visual Studio 2015 and make use of the new Roslyn compiler capabilities to display method parameters used in the method body, as well as local variables used in code, in a different colour than other identifiers. This should help me distinguish locals from instance fields. I'm only interested in highlighting the C# language, but don't mind if it also works in other (CLI) languages.
Where would I start to do this? I cannot find any relevant information about this task.