Which color Gravel to accent Carpintis?

[AllAlaskan]

I am just curios as to what you guys would think would be the best color gravel to use to accent the color of a Carpintis? Locality is Vontehillo
so mostly green than blue. Right now I have a brown,tan,dark brown type mix.

 

[the animal guy]

Natural colors

 

[duanes]

I use a thin layer of pool filter sand mixed with a little brown aquarium gravel.