The very center of the path is pretty dark, but still somewhat visible. I can't make out the details on the dirt texture - it just looks dark brown.
Colored lighting is done by multiplying the RGB values, so if you have pure yellow light (1, 1, 0) and multiply it with a pure blue texture (0, 0, 1), you'll get black (0, 0, 0). Naturally, the colors and lighting won't be "pure", but the effect is still the same -- you'll get some dark, muddled color which is hard to see.