The latest Edge Canary build is adding a new personalization feature that lets users apply custom accent colors to the browser theme. This feature is currently hidden under an experimental flag (spotted by HotCakeX in the Edge Insider forums) and must be enabled in order to show up in the settings.
Heading to edge://flags and enabling the ‘edge-color-theme-picker’ flag adds an ‘Accent color’ option in the Appearance section in Settings. The option lets users select from 15 available colors. These accent colors apply to the title bar, toolbar, and the new tab page, irrespective of whether the browser is set to dark or light themes. However, the feature still has some rough edges since it is still in the early development states.
The accent color option differs from the third-party themes that can be downloaded from the Edge Add-ons store or other stores. While the toolbar icons also adapt to the accent colors to match the theme and provide sufficient contrast, the context menus still adhere to the light/dark browser themes and do not change depending on the accent color selected. The custom colors can be simply disabled via the ‘Remove’ option right below the palette.
The feature can be enabled in Edge Canary build 89.0.731.0 or newer. Since it has just shown up in Canary releases and is still hidden under an experimental flag, it will be a while till it shows up in regular builds and eventually in the stable channel.