I have a wide-gamut display and I can notice the difference between applications that incorrectly "stretch" sRGB to the display gamut versus apps that actually colour manage and map the colours correctly.

No app on Windows colour manages the UI widgets such as the icons, toolbars, etc... This is because the WDDM shell doesn't do any kind of colour management, it leaves that up to the application developers.

The sad thing is that Vista introduced an extremely wide scRGB gamut and WDDM had a number of internal features built around it. Unfortunately, it was only ever enabled for full-screen games, video overlays, and for internal use by apps that do colour management. They should have converted the entire desktop manager to use it.

https://en.wikipedia.org/wiki/ScRGB