I know you can change elements of web pages and some aspects of the outer "chrome" via custom themes, font family settings, etc. What I can't seem to find is any way to change the background of the settings menu (and submenus) in Chrome. I would prefer it to be a dark them vs. the black text on white.
A similar, related issue is being able to manipulate the overall size of all chrome elements, be they menu fonts, tab fonts and sizes, and icon sizes. My elderly mother, who's having a harder and harder time seeing things due to macular degeneration, would benefit greatly if I could configure these items, as she currently has to use a magnifying glass to read some items.