Here at Male Order our mailbag – male bag?

– tends to be empty most of the time. But after last week's musings on the fashion problems posed by the new film version of The Great Gatsby it has bulked up considerably, like a supermodel gorging on Vimto and white pudding suppers.

The deluge of letters – two so far, but who's counting? – has nothing to do with how to find a decent pink suit or what to polish two-tone brogues with, however, but concerns instead my comment about F Scott Fitzgerald's description of Jay Gatsby's chauffeur's uniform.

The author calls it "robin's-egg blue" which in my book (The Observer's Book Of Birds' Eggs) is wrong, because robins' eggs are cream with mottled brown bits. Or so I thought.

"The book is set in North America," writes correspondent number one. "Fitzgerald would have been familiar with the North American robin whose eggs are indeed blue." He's thoughtful enough to append a photograph which does indeed show these blue eggs.

Correspondent number two writes in a similar vein: "The Americans call a different bird 'robin'. It is about the size of a blackbird, with a reddish breast, and I suspect its eggs are blue. A reference to this was made by Joan Baez when, adoringly, she referred to eyes 'as blue as a robin's egg'."

The line is actually "I remember your eyes/Were bluer than robin's eggs" and it's from a song called Diamonds And Rust, which is supposed to be about Bob Dylan (don't take her word for it, though. It'll take you a couple of hours, but if you can find a shot of Dylan on Google Images in which he isn't wearing sunglasses, you can confirm it for yourselves. He does have blue eyes). The American robin, by the way, is a member of the thrush family; the European robin is a flycatcher.

You may also like to know that robin's-egg blue is an actual colour – at least according to crayon and pencil manufacturer Crayola, who popped it into its official colour pantheon in 1993 along with other new entrants, Razzmatazz (a sort of nasty raspberry colour) and Mauvelous (mauve, of course).

As Pantone 1837, meanwhile, robin's-egg blue is officially known as Tiffany Blue and is used by New York jewellers Tiffany & Co. Social upstart Jay Gatsby may not have known that, but Fitzgerald certainly would. All this is making me think the damn chauffeur should have been the central character in the novel – especially when I learn that in something called "gay leather subculture" a bandana in robin's-egg blue has a very particular meaning.

Sadly it isn't one I can share with readers of a family newspaper - although if you find a copy of The Observer's Book Of Birds' Eggs there's a clue on page 69.

barry.didcock@heraldandtimes.co.uk

Twitter: @barrydidcock