Switching the theme
Switch the dashboard between a light, dark, or system-matched color theme.
The dashboard has a light theme, a dark theme, and a System option that follows your operating system's appearance setting. You can switch it from two places: the sidebar user menu, or the Theme card in your account settings. Both control the same theme. The user menu switch keeps your pick at once; the account settings card previews it and keeps it when you click the page's Save.
From the user menu
Pick Light, Dark, or System on the Theme row's three-way switch. The dashboard switches immediately, with no save and no reload.
From account settings
Your account page has a Theme card of its own, with the three choices drawn as small pictures of the dashboard: light, dark, and, for System, half of each.
Click your avatar at the bottom of the sidebar to open My account.
In the Theme card, pick Light, Dark, or System. The dashboard previews it immediately.
The card's pick waits for Save
Until you click Save, a new pick on the card is an unsaved change: the page shows Unsaved changes, and leaving the tab asks whether to stay, discard and leave, or save and leave. Leave without saving and the dashboard goes back to the theme you had before. If the same Save also carries a language, time zone, or profile change that fails, the theme isn't kept either and stays as a preview until you save again.
System matches your device: the dashboard is light when your OS is in light mode and dark when it's in dark mode, switching with it.
The theme is separate from your language and time zone: it's a display preference remembered in your browser, not saved to your account, so each browser keeps its own theme, even though its card is on the same account settings page.