Look at the attached image:   the nearly unreadable X3 event list, and the same thing viewed through windows magnifier, no zoom, just changed background color and text colors.   You can not change the background of the event list: please FIX IT.  You can not change the font size of event list: please FIX IT.     Changing text colors is very little help with that background, I've tried nearly every color imaginable.   [edit] ironically, as an image, the original shows up better, but on my LCD screen it is impossible to read. 
 
 
 

Yes, there is no limit what you need to customize. So different screen resolutions available, and multiple monitors, 4k monitors and I don't know what else.
 
Maybe something of the style that Windows have, choosing large/medium/small system font or similar. The same exist for icon images on shortcuts etc.