Starting with version 1903, Windows 10 is introducing a true system-wide light theme that brings light colors to the Start menu, Action Center, taskbar, touch keyboard, and other elements.
Right-Click ➡ Personalize ➡ Color ➡ Choose You default Windows Mode "Light"
The new color scheme is available selecting the Light option under “Choose your color” drop-down menu from the “Colors” settings page.
Windows 10 1903
Windows 10 version 1903, May 2019 Update, is the next major release available for compatible devices starting May 21, 2019. This is the first of two feature updates coming in 2019, and it delivers several new features and improvements meant to enhance the experience.
The new version isn’t a massive update, but it’s a smaller release that includes many incremental changes and a few new features around performance, design, security, and productivity.
Windows 10 2019 Update Version 1903 Review: 
How to enable/disable Reserved Storage on Windows 10 Review: 