For simpler syntaxes like C or Java, I think the highlighting adds little. But as a language allows for more complex things like monkey patching or helper methods and the like, a little bit of color is really helpful. Knowing immediately that a method is built into the SDK or that it's some monkey patch that's been added gives me better understanding on what the code is doing.
That said, "go to definition" and "autocomplete" are the most important tools to me when it comes to coding.