Annealing color

UndFrm

Sergeant of the Hide
Full Member
Minuteman
Dec 13, 2022
117
19
CA
I recently acquired a batch of fired brass (unknown how many times fired), inspected it and went to the annealing step.

Within 2 seconds under the flame, the top gives out a florescent green color on it. This happened to almost 90% brass from the batch. I have inspected for any visual markings and it seems to be fine. The brass is Peterson 284. Would anyone know anything about this bright green color? It goes directly to this color, without passing any red or orange.
I'll try to capture a pic the next time my annealing machine is out.

Thank you