Did I screw up? Green ashes.

Hi everyone.

Lately I have been letting my neighbor stack some old cedar decking in my burn pile for disposal.  I checked before each drop off and he knows and understands my intense dislike for burning anything with green wood (CCA, etc).  As I said, these were all cedar planks that had rotted and we had quite a pile of them.  

Last night we burned them--what a blaze!  Today I checked on the still-smoldering ashes and I noticed that some of the ashes had a slight olive-greenish hue to them--certainly not everywhere but it was noticeable.  I should also note that the coals underneath are still very hot, and before sunrise this morning the pile of "ashes" was still glowing orange-red.

Does anyone have any idea what that greenish hue might be?  As I said, I checked for treated lumber and I am not familiar with burning cedar--is this just how cedar ashes look?

Thanks in advance for anyone who has any ideas,

Eric