I managed in my own MyWin8 to get rid of this blurred stuff, basically creating bmp so no transparency and similar things.
But get some things transparent now in caption when windows not active.
I thought seeing this remark "title bar blur features enabled" that I could turn that off instead of learning everything making my own skin.
It took some hours to get that far.
But mostly run Classic skin with win95 type of look and that is very good too. Actually many really good.
I imagine there is some registry setting or group policy in windows to turn that blur stuff off. I have not found among regular appearance settings through System and Advanced either. There is some policy setting to turn off blur of background on lock screen, or login screen.
Easier to do that, and then just use Win8 skin as it is rather than learn the full procedure getting myWin8 all good.
But I'll fix you a screenshot tomorrow of Win8 how it looks. All kinds of shadows and blurred stuff around text in caption, so just about readable.
I don't have 4k monitors, so just 1080p but dual monitors so 3840 wide. Maybe it looks dandy on 4k monitors.