Have you tried System Preferences > Accessibility > Display > Reduce TransparencyYou can (finally!) turn off the horrendous wallpaper tinting in the newest beta.
View attachment 940715
Still no option (that I can see) to disable just the menu bar transparency.
 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
		 
 
		 
			 
			 
			 
 
		 
		 
 
		