Just to add to the list of very bespoke hotkeys, I have one to change the "default" text color of e-mail replies in outlook. If I press Win+A and the active window is part of outlook, it will go into File, Options, Mail, Stationery and Fonts, "Font" for replies, and open the color picker

Helpful when I'm trying to send inline responses in an otherwise busy thread with multiple colors... and then I can switch back to my default blue after that with the same keystroke