Operating system: Windows 10 64 bit
Graphics card: Nvidia GTX 750 Ti
Short description of error
The background color in the Workbench Renderer is not solid.
Rather, it has a very fine pattern.
This is especially apparent, if the background color is set to black.
Exact steps for others to reproduce the error
Just render. It will look like this:
Zoom anywhere into the black area, and you will see the pattern. I would expect it to be perfectly black.