I like flat black theme
Kamelito
Why? Flat themes are one of my major objections to Windows 10 (along with the continuing downgrade of the Start menu).
I use Windows 7 Ultimate and Windows 10 Professional (and just retired a machine the required Vista - again I used Ultimate - yeah that Windows variant, which after much upgrading finally worked pretty much like Win7).
Frankly, I find the themes in Vista more pleasing to the eye, and Win7 is a great mid-point between problematic Win Vista, and the really sucky Win8/8.1.
Kind of the upgrade to WinXp that should have been introduced in the first place and one of the best looking and functioning Windows variants.
Win 10 can be annoying with its flat look. It took me a few minutes just to work out the changes in the appearance of Calculator so that I could cut and paste to that.
The opinion that flat themes prevent distraction from program content is just that, an opinion.
A good looking desktop involves all elements, and I just find flat themes far to stark and ugly.