On Wed, 20 Apr 2005 13:34:20 -0700, Mark Haldorson
A coarse pigment like that won't work in a true "stain", but if it's
actually more of a glaze (a coloured varnish) then it should do. Don't
use too much, or you might find the finish tends to flake.
I don't know what green concrete pigment is made from. It's not as UV
stable as the red or black pigments, but it's probably OK for timber.