This does this:
STOCK
EDIT
You can see my 123456789 50% grey test card texture. There is no terrain texture.
In the EDIT shot, you can see the noisesmall texture from up high and the ground terrain texture is overlaid with more contrast and even overlaid over the airport texture (which results in a smoother blend) but using a completely different alpha effect.
Unfortunately, while it does look better as it's more detailed from higher up, thanks to the noisesmall being visible, it still doesn't kill the weird colours.
Another great find Mustang.
Keep at it.