Don't Spit — Remember the Johnstown Flood
As far as I know th "no brown in town" refers to business dress, and it's an old rule that doesn't apply anymore... I also heard somewhere that you shouldn't wear brown in London at all, but I'm sure this rule is not for the London Ivy crowd...
"No brown after six" is an old fashioned thing, too, I guess... Probably from times when people ore formal or semi-formal evening clothes after six...
NBIT is for plebs.
Their betters always wore it & still do.
Who makes these Andy-ish rules up anyway?
Many of these sartorial rules come from Victorian London - A place really looked down on by the left-overs of both Georgian & Regency London.
Victorian style was deeply middle class.
Just like Queen Victoria herself.