With regard to Symbol Coloring, two points.
First, opening the setup screen is an exercise in visual overload. There is nothing to give you a much clue what to do next. Well, except to read through all the Help. "Don't Make Me Think" is a good book to read. Coders, as users of programs, are just Plain Dumb Users of your UI.
Second, I would have thought that Symbol Coloring, to be easily usable, would act as Delta to Coloring. From what I can see, it doesn't. One has to build (code, really) a scheme; perhaps one for each language one needs to use. For the java framework coders that would be: java, xml, ini, jsp, jsf, xhtml, html, xsd, js, sql, template, and likely more that I have since forgotten. Or, what could be worse, figure out a single scheme which supports all of these without collisions.
In previous versions of SE, I found, in the java framework world, the need for one, may be two, additional categorizations in Coloring to get sufficient granularity. There are, after all, only *6* colors, primary and secondary; 12 (max, I can't remember both sets right now) if you differentiate light colors and pigment colors.
OTOH, instead of Symbol Coloring (as implemented) if SE coders had built either:
1) support for multiple embedded languages, thus helping <language du jour> web framework coders
2) full support for 2 additional <language du jour>s (and how did D bubble to the top of the sort, anyway?)
I suspect that the number of happy campers would be higher and the number of grouchy campers lower than what has occurred.
2 pence