Check this video
https://www.youtube.com/watch?v=8xlG9Ln5o30&t=1083sIt will be the VideoDAC. You probably have a non-responsive section on the slider. Just do it very slowly using Pro-Tracker and see if at any point it moves but the colour doesn't change.
You can change your Workbench colour palette to compensate for the lost colour, which interestingly will also show what colour is causing the problem. Just have a play.
I have three machines now with the dreaded tint issue. I just don't let it bother me as its the grey that is mostly affected. Like I say just compensate with the WB palette or choose another colour scheme. This is one of my A600s with it.
https://www.scuzzscink.com/amiga/scuzzblog_september21_1/car_sbd_090921_10.jpgWorth also checking over and maybe changing your monitor cables.
