Looks good from the distance but not so great when you get really close. We will solve that by adding a Turbosmooth modifier, but beware, Ground01 will now have 320000 faces and there may be more of those performance issues, so in the Turbosmooth options, set the Iterations to 0 and the Render Iterations to 1, so it only applies the Turbosmooth when we render.
Now off to the mapping. Select a new material and name it GroundMaterial, then apply it to Ground01. Add a Mix type material in the Diffuse Color Map. In the Mix material, set the first color to R:35 G:15 B:0 and the second color to
R:255 G:205 B:100. These will be the colors that the terrain will have at higher and lower altitude. We will make this possible by selecting a Falloff map for the Mix Amount map
Now comes a tricky part. We will go into the Falloff map. Leave the Falloff Type to "Perpendicular", but set the Falloff Direction to "Viewing Direction ( World Z-Axis )". Next, in the Mix Curve tab, we will press Add Point and add a new point to the curve, which we will then right click and set to be "Bezier-Smooth". Set the curve points to look something like this: