How-to
How do I change the theme and background effects?
In short
Theme changes the colours of your admin sidebar and adds a slow animation behind your admin pages.
Open Theme in the admin menu, under System. The page has three tabs.
On Sidebar color, click a colour for the sidebar and one for the selected item. Live preview shows the result.
Click Save colors. Nothing changes for anyone until you do.
Open the Background effects tab and click a card to preview that effect on the page.
Click Save effect to use it for all your staff.
Good to know
Theme changes your admin area. To change your public site colour, use Branding in Settings.
Restore default puts the sidebar colours back.
Effects pause when the tab is in the background, and people who use reduced motion see a still picture.