Purple under hazel bark

[Rambling Rob]

Hi,
Peeling the bark from some hazel revealed this striking purple coloration.
I know many dyes are extracted from plant material but have not found any reference to purple dye from hazel, and have not noticed anything similar beneath the bark of other wood I have stripped recently. The colour is not evident on the surface of the bark and occurs in a very shallow layer.
Earlier I posted this in the trees section where Dorts suggested a fungus might be involved.
Any suggestions please?



Thanks for looking,
Rob