I was given a Holly log years ago that had been laid flat for a year. When I finally cut it the whole timber was a horrible grey colour. I was later told that it should have been dried upright, the same way up that it grew. Hope this helps.
I have some timber reputedly from a handkerchief tree. It turns like a cross between elm and walnut. Similar colour to walnut. I would like to know if you still have any left. I want to see an enlarged image of the end grain known to be h/chief tree to compare the pore structure with what I have...