Users can use a browser plugin like Stylish to do this themselves if they desire. Of course, I'm sure it's fairly trivial to make a plugin that would do this.
I've seen some demand for this as of late. It would be a pretty massive overhaul so I can't promise you a definite timeline on this as we have a ton of other things to get out for 0.5x next month, but will keep it in mind in future 🙂
