Terrain Textures suddenly extremely muddy

So, I've been working on my game for a long time now, back when Unity 3.3 was out. I have since upgraded to 3.4, and again to 3.5. Anyway, I'm working with a 2000x2000 terrain model, 513 heightmap resolution, the Terrain Toolkit addon, and three 1024x1024px textures. Now, everything was working swell for a long time now, but recently I decided to add some trees to my game. I created a tree, which made one below the terrain. No big deal, I was going to make it a prefab anyway. But after I made the tree and went to mass-place it, I noticed that my once moderately detailed textures now look like a single flat color (the only shading is due to the sun.)

What happened? Is there any way I can fix this? It looks the same when I export the project too.

 

I also found the problem, but I also don't know how to solve