I am sure that the following is not the explanation for your green
honey (the author grew up in California), but perhaps you will find
it interesting.  I told my wife about the green honey, and she
provided me with this quote from "The Art of Eating" by M.F.K.
Fisher.
 
"Mrs. Cheever, for instance, would get a consignment of
strange honey from the Torrey pine trees, honey which only a
few people in the world were supposed to have eaten.  I
remember it now with some excitement, as a grainy greenish stuff
like some I once ate near Adelboden in the Bernese Alps, but then
it was to most of us just something sweet and rather queer to put
on hot biscuits."
 
John Naples