On a serious tone - and I have to confess I feel responsible for sidelining your original question – wear whatever you like.
This topic has been discussed before. General consensus seems to be that in a Spam Can you are best off just wearing normal casual gear – go for fabrics that are man made as they give you better protection from fire (if they do burn they do not melt into your flesh) and also prevent you looking stupid.
Wearing a white flying club shirt and black trousers may well mean that you are dressed like an instructor. At the end of the day it is entirely your own choice – if you wanted to wear a Gro-Bag and G Suit that would be your choice, likewise if you wanted to wear your smalls and a white shirt, well that is up to you.