I am experiencing the same with my MBP 2018 i7-2.6/560 when the 560 is doing the works. I tried it on a MBP 2016 i7-2.7/455 and it is doing the same. Checked a display model i7-2.2/555 at the Apple Store and it was also doing the same when the dedicated GPU was activated. I noticed it changes with color temperature settings, when Night Shift was activated. This "effect" is not present with the integrated GPU on those machines.
When testing it on a display model, switching of GPU setting is not selectable due to locking of the machines, but I triggered it by simply loading up Final Cut Pro and as soon that was loading the green distortions were clearly present.
All was tested on Mojave. Couldn't test it with High Sierra yet. Will do so on the MBP 2016 as I get to restore it soon and will restore to the OS it shipped with and then upgrade.
When testing it on a display model, switching of GPU setting is not selectable due to locking of the machines, but I triggered it by simply loading up Final Cut Pro and as soon that was loading the green distortions were clearly present.
All was tested on Mojave. Couldn't test it with High Sierra yet. Will do so on the MBP 2016 as I get to restore it soon and will restore to the OS it shipped with and then upgrade.