Useful info thank you but the normal TV picture and sound are fine.
The problem of the TV picture intermittently switching to what looks very similar to complementary colours for a minute or so and then returning to normal does not seem to be related to the problem for which your solution is designed.
This seems to be directly related to the use of HDMI cable taking the picture and sound to be displayed on the TV screen. For most of the time it works faultlessly, but brief glitches occur during HDMI transfer which do not happen normally. It seems that a glitch triggers the change in picture in both cases.
I should add that the picture does not become negative as in a photographic image.