Nothing new here. You are using a high contrast black ribbon ( Black Buttonface and white buttontext) and whatever program you are using for transparency is registering the black as transparent
Black is Fonts, Colors, & System Metrics > Fonts & System Metrics > BTNFACE:COLOR
White is Fonts, Colors, & System Metrics > Fonts & System Metrics > BTNTEXT:COLOR
Green is Fonts, Colors, & System Metrics > Fonts & System Metrics > BTNSHADOW:COLOR
Orange is Fonts, Colors, & System Metrics > Fonts & System Metrics > GRAYTEXT:COLOR
Blue is Fonts, Colors, & System Metrics > Fonts & System Metrics > HIGHLIGHT:COLOR
Red is Fonts, Colors, & System Metrics > Fonts & System Metrics > HIGHLIGHTTEXT:COLOR