I use the integrated graphic card from the processor.
The display is a LG TV OLED55BV6, linked with HDMI cable.
I've try almost all setting up from the TV and the radeon, also RGB or YCbCr pixel format don't change anything.
On the "background" appear like a chessboard light gray square mainly revealed with picture in warm color orange-red but also on white page (the square looks like more light blue)
I see it with a movie and on image like wallpaper, it still present when I use picture program like paint or gimp.
I don't have this issue with an other computer with Intel graphic card or on the TV itself.
When I upgrade the driver to the last 19.4.1 I have issue with Mediaportal that use directx9, it cause a error directx layer exception with crash of the program.
Return and reset to the base driver 19.1.1 has resolve the issue.
Here below the screenshot
Thanks for any help