I would suggest that many GT cars are and potentially all could be pretty easy to ID in the dark regardless of headlight colour these days, thanks to the light strips.
There's also only one type of GT car anyways, so it's not like in the old days when whether it was a LMP2 or GT1 with roughly the same straight line speed in the mirror made a significant difference to a GT2 car, it's either going way faster than you or it's another GTE.