What do people think of HazeOver ?
There are several free competitors: Doodim, Hocus Focus, Backdrop, and Isolator, DeskCover.
Copypast - the author took the idea from Izolator or from other free alternatives that appeared earlier and implemented HazeOver
This has been a standard app on my machine. It is one of those utilities that does its work day in and day out making my experience a much more pleasant one. I have wrestled from time to time with how strong to set the opaqueness of my Haze in order to give me a good workspace. I have also not toyed much with changing the color of the haze, but expect this could make for a fresh workspace, if needed.