[20] Fluent's key principles, or "blocks" (Light, Depth, Motion, Material, and Scale), turn away from the flat concept Metro had defined, and while preserving the clean look and feel Metro introduced, Fluent renews the visuals of Aero, a design approach that was introduced in Windows Vista and Windows 7, including blurred translucency, parallax animated patterns, drop shadows, highlight effects following mouse pointer or input gesture movements, and "faux materials" Metro once discarded.

[25] Furthermore, with the release of Windows 11, Microsoft has slowly been removing its use of light effects in general, instead providing intractability though animations.

Occluding materials, such as acrylic and mica, form the base layers under interactive UI elements.

Transparent materials like smoke are used to emphasize immersive surfaces:[35] Both Acrylic and Mica are disabled in a specific window when the app is no longer selected.

[47] These icons started appearing through Microsoft Store updates to those apps, beginning with Mail and Calendar.

[51] On July 15, 2021, Microsoft announced a complete redesign of its emoji library in order to align with its Fluent Design.

[52] Aiming to make Windows as consistent and accessible as possible, Microsoft made over 1,500 emoji open source on August 10, 2022.

It provides a set of pre-built components that can be used to build applications for Windows, iOS, Android, macOS and the web.