- Click your profile in the top-right corner of the header.
- Click Dark mode to flip the switch on or off. The menu stays open so you can see the change.
Follow your device instead
Go to Settings > Branding and set Display preference to System preference, Light mode or Dark mode. System preference follows your device's light or dark setting; it is the default until you pick a theme yourself.
Good to know
Your choice is saved to your login, so it follows you to other computers.