My niece wants this cake for her birthday:

(Sorry, I don't know where she got the picture from to give credit)

I believe I can get the carving down pat to look similar, but not as amazing. However, I do not have an airbrusher to get the real affects of the coloring. 
And there are not color mist for brown, I was wondering if anyone has dabbled with luster dust- well.. colour dust and steam? like you would with a gumpaste flower? would this work well? tho tricky to put steam on this cake.. i'm desperate for ideas!