I Fixed the problem myself. Notes are: When I took screen shots of the problem and sent them to some colleague they said everything looked the same. I have checked it myself on my laptop screen + My phone's screen. it did look the same. This info made me think that this is not a software issue but rather a Hardware issue. I have replaced My HDMI Cable + My USB-C to HDMI Adapter (which is, a pretty expensive one) to an "Original" Apple adapter. after completing these two simple (but expensive) replacements the problem fixed itself. It appeared that the problem wasn't only happening in Lightroom, but all over MacOs. It took me time to notice because the greenish tinting was really really slight and appeared stronger (or more viewable) on B&W images, where the tint actually became visible. Conclusion: Check you hardware. ... View more