https://www.bleepingcomputer.com/news/microsoft/windows-10-build-18282-released-to-insiders-with-new-light-theme/

Windows 10 19H1 Build 18282 is now available to Insiders in Fast and Skip Ahead Rings. Today's preview update for Windows 10 brings a light theme to Start Menu, Taskbar, Action Center and other elements.

In a blog post, Microsoft notes that you will be able to choose between the real light and dark shell in Windows 10. If you select Light under Settings > Personalization > Colors, the system color (Start menu, Taskbar, Action Center) will change to light and it looks fantastic, thanks to the new Windows 10 Hero wallpaper.