Not quite.

You can set an Accent color and either a light or dark background - that’s it. You can’t specify each component color or named system color - such as separately specifying the colors of the scrollbar’ track and thumb - or icon text - or button shadows - and so on.

The old “Desktop Themes” feature for Windows 95 Plus! and Windows 98 let the user radically change the appearance of Windows - for better or for worse - when was the last time you saw a custom desktop icon pack or purple 3D face color?

But yes - all of this assumes the user is aesthetically capable - but neither was Microsoft: Google Image Search for “windows hot dog stand”. Be careful, you might get a migraine.