It is hard to get the grass look well in all light conditions and sun angles. IMO good textures of grass terrain and good shading of it is much more important than occasional vertical 2d fins, that is considered as 3D grass. 3D grass is nice to make tall weeds, and some occasional weed or grass here and there. Firs of all colors is colors. As someone said grass and leaves has a nice effect when the light comes from behind, this is hardly ever represented in games. GTsport does that rather well, they really did take specularity into account, and did not compromise it. And they does use 3D grass only occasionally, does,'t lay it evenly through all areas...
for me iRacing has the best gras. And it's not about colors or optics but the effects and how it interacts with, lets say cars . When you slide on the gras and patches and particles fly around. Or the visible deep skids you do when you brake on the grad etc.