But if someone wishes to be known as a menber of the opposite gender to their ascribed gender at birth, surely they'd wish to be seen in the same sort of clothes worn by others in their "new" gender?

If not, they could have just regarded themselves as the "new opposite" and carried on in their old clothes and old hairstyle?

I don't think they'd want to be "neutral" at all. If a "neutral" uniform had been in force before their change, would they have any need to "announce" their change of gender?