"correct landscape colours" depend on many, many factors:
Daytime, date, blue sky - scattered clouds with shadows - overcast sky, degree of humidity in the air, seasonal vegetation, even the latitude on earth. Perhaps many more ...Rodeo
And most definitely Camera and screen gamuts, dynamic range and white balance settings and capabilities.
Since both are shown on the same monitor, it's fair in that sense that the display is somewhat taken out of the picture (pun intended), but the camera used to take the real picture and the screenshot may have a different white balance. I can take real picture that look just like the aerofly pict in your example.
You may also notice that in the two examples you provided (beginning of thread and last post), the "real" pictures have very different characteristics. In the first one the shaded part (real pict) is essentially the same saturation and about same color temp as FS2 just a bit less exposure (normal, in the shade), the sunny part is warmer, (normal too, sun makes it warmer in colors). To me, it's all normal and fine as FS2 doesn't have the sunny/shade contrast like this so FS2 is in the right middle, because it doesn't have the sunny/shady effect, and it's probably really hard to do. In that case, to my eye, FS2 looks like the right saturation, a bit less contrast, and a mid level white balance (not sunny, not full shade), so just about where I'd expect it.
Case in point, cameras have different white balance settings for either case, because they just cannot do justice to both at the same time like our human eye can. So in your first case I wouldn't adjust the FS2 pict as either way (towards shade or sun) would make the other one even worse.
Now the second picture, which clearly show a general difference, the main difference between the two picts (real/FS2) right now is color temperature (i.e. white balance to simplify), it may also be slightly more saturated for the "real" one. I would be really careful there, as the difference between looking with your eye (which on top is different for different people) and a camera is already very hard to judge. If you don't believe me, look outside your window and take a picture, now compare the two. Now tweak white balance, saturation, tint, exposure, etc.. until you think it's exactly the same SIDE by SIDE (picture to real view with your eye), that should take some time, if one ever finds an answer. Most likely the best will always be some kind of compromise.
So the point here is that it will be very difficult to have anything look satisfactory to everyone and in every conditions. We all have different sensitivity, and the human eye is always more capable than any camera.
One could, justly so, argue that it is irrelevant in the sense that the same person/eye looks at real scenery and at artificial scenery, but it makes it difficult however to have artificial scenery be the same feeling for everyone. I can make artificial scenery that looks just like real to me, and someone else will find it different because their eye is more sensitive to something else (color balance, saturation, light, etc..).
Here as I thought, I had to make it way cooler and a very slight increase in saturation. I still didn't get the blue right (water) as they are fundamentally different. If I get a similar blue the rest of the colors will be completely off. Personally, I wouldn't want FS2 to look like this (way too "blueish"). Now does FS2 have the perfect white balance and compromise (contrast, temperature, tint, saturation), maybe not. It may be slightly too warm for most people and slightly undersaturated (what you refer too as "greensish", but is more "reddish"), but if so, not by much at least to my taste.
FYI the "real" picture to me, with a somewhat trained eye, looks way too cold in white balance and undersaturated. It's part subjective, part experience, and part the conditions of the picture (could be the camera, would be atmospheric conditions, could be the glass filtering, or any combination thereof). On the other hand the FS2 pict is too warm, and slightly undersaturated also.
Both could use a bit more contrast too, but that's expected with atmospheric haze, so I'd say in that sense it's a good match and a good setting.
The point here is that, to me, neither look real, they both look like a picture taken of real scenery through a camera that has slightly off settings for the conditions (everything is too blue, blue greens, greys are too blue on the "real" one, too warm for the other). I'd say something in between looks "real".
I put "real" in quotes, because it really is a representation of real, though a certain camera with its particular settings and performances. We don't have a real reference here, and we can't no matter what we do, it will always be through a camera.
Another point, it may just be that the setting of anybody's particular display (screen or otherwise) is off too. Just like cameras, displays (screens or otherwise) have a certain setting, and that influences picture colors perception. Not the case for you as one pict is too cold, the other too warm, but just be aware of the issue when speaking of colors. It also means that a given color set, doesn't render the same for two different people with two different displays.