That to me feels like a very nice hierarchy:
A few basic, common options available in the main UI.
A few more-advanced/less-commonly-desired options available in a part of the UI that's labeled "Advanced". Things that mortals-but-not-noobs would be interested in. Novices actively don't want to hit Advanced but the sort of user that would be interested in these options goes right for it.
Then really exotic options are available through an interface that takes up absolutely no UI space but is easily accessible by most of the kind of people that would want such things.
Where you do see lots of "Advanced…" buttons is in System Preferences…
Security & Privacy
(Displays - Calibrate has an "expert mode")
Mail, Contacts & Calendars - for manual mail accounts
Network - big advanced section
Bluetooth
(Zoom in Accessibility has "More Options...")
So there's a few of them, but I wouldn't say lots.By the same token there's no way to do this for the web. (you can override style sheets willy nilly but don't expect a lot of stuff to work).
I suggest you might need to get used to reading text on backgrounds that aren't a "pleasing greenish" color, write all your own software, or learn to live in a world of pain.
Instead of allowing people to set the default edit field background to magenta (which windows does) Apple spent engineering effort on, say, universal access.