There are numerous methods of dealing with it. Some examples:
Slightly tint the color using noise
texture.
Change to different tiling using
camera distance
Multiply existing version of the
texture, with the same texture, but
at different tiling, while
desaturating and adjusting
brightness. Link with example.
This should be your primary choice
for mobile.
Add some sort of perlin noise normal
map
Do a highpass on your textures
before importing them to dim large
scale variations