Could you try a picture test to see if the shading still shows? Go to Menu > Support > Self Diagnosis > Picture Test. Are you able to send us a photo of the brightly coloured beach scene?
On top of what @ChrisM said, can you confirm if you get this on all sources?
By just looking at the photo you posted it looks like what happen on Netflix when you bring up the options.
ALSO, I just noticed you're watching The Office!
"Do I want to be feared or loved? Easy, both... I want people to be afraid of how much they love me" - Michael Scott.