PS: Ming, stop all that english slang-talking, my lamp-mind are fried every time i read smh from you!...
But VikS, we love Minglish!
(btw, I think I probably need to turn down the contrast on my monitor here)
What I think I'm seeing is the high-lighting of the 3D trees in the close viewpoint, and a color difference between the switched-out appearance of
the forest as it transitions into the background. Here's two illustrations.
In this sceenshot I can't see any color variation between the foreground trees (1), and the connected forest as it switches into the background (2):
However, in this one, and perhaps because of the greater intensity of the light-source (and by the shadows cast on the rolling terrain), the foreground trees (1),
seem brighter in color than the connected background forest (2):
You're probably right guys, it is kinda nit-picky, and the evolution between near-shot and far-shot views is working really well.