John K Jordan
If you get the AAW emails, may have seen this, in the email I got yesterday. If not an AAW member, it's worthwhile joining.
attributed to Alan Miotke, Mount Prospect, IL
This test doesn't address if any color change is due to oxidation. I have some old cocobolo and while the inside is beautiful with color the outside is dark brown all the way around, almost black, and extends a bit into the wood.