Good language-aware syntax highlighters do a lot more than highlight keywords and other syntactic things, and can make code more readable in a nontrivial way. For example, Eclipse's Java editor will color things differently based on the scope you pull it from, which lets you distinguish local variables, non-static fields, static fields, and inherited fields. It does a similar thing for method invocations, including a strikethrough for methods marked as deprecated. This saves having to manually go to a bunch of definitions in order to get the proper context when reading code you're not familiar with.
