"Differentiate without color" setting in Accessibility System Preferences
The only change I've found so far is changing the dots in Messages, as some other users have pointed out. I couldn't find any changes in Finder, which surprised me, since Tags would definitely benefit from this feature.

EDIT 1: This book excerpt would seem to corroborate that: https://www.safaribooksonline.com/library/view/os-x-yosemite/9781491948484/ch09s02.html