Windows 10 May 2019 Update has a new light theme for Windows desktop. Light and dark themes are available in Windows 10 version 1903. Windows 10 has previously had two color modes – light and dark. The light theme allows apps and programs to use white color, while the dark mode enabled the use of darker colors and accents. New light theme wallpaper lets you mix and match components of both themes such as combining light apps with dark core UI elements or dark apps with light core elements. Microsoft has also updated icons of apps such as Microsoft Store, Settings pinned to the taskbar when you switch to light theme.
Source: https://www.bleepingcomputer.com/news/microsoft/a-closer-look-at-the-new-windows-10-light-theme/