on a secondary research it seems I can't use green (or maybe just a strobing green) since it's for volunteer firefighters and volunteer EMS.
oh well, if DX only stocked amber.
Seeing as they have red and green it's possible they will stock amber eventually
I'm not sure you are allowed amber over here, I think it's only allowed for turn signals.
You could always fit an amber LED ?
EDIT: thinking about it, breakdown trucks and road gritters have amber lights