: Right-click on any empty area in your Arc sidebar and select Theme .
There is no "Theme Store" pop-up inside Arc Browser yet. You do not "download" a theme file to your hard drive. arc browser theme download
While there isn't a single button to "download a theme for all tabs," the Arc community shares "Boosts" via link. You can click a shared link, and the Boost is instantly applied to that site. : Right-click on any empty area in your
You will see a built-in palette of 24 premade gradients. These are lovely, but they are the "basic" pack. To go further: arc browser theme download