Not too far off topic, but in doing the rock work on my HOn3 layout all rock in NM has been a problem for me to get it right. I have taken many pics of the areas I am modeling and in most cases the reds are more brilliant then they really are. A lot of pics are taken more in the afternoon/evening then daytime and the colors show up much more red then they truly are. All this being said, don't get too red in your modeling of these areas, your layout lighting may make your layout look as it's on fire.
trainman