All fashion makes a statement. I wear Gucci. You have taken your hem up. Has she removed the curtain rings from that frock? But the statement made at the White House holiday (Christmas) reception was enough to provoke the hostess to exclaim: “Never darken my Dior again.”

Three ladies turned up wearing the same red dress for la crème de la crème of American high society. Their intended statement was: “Admire. This is Oscar de la Renta. This is exclusive. Look on my frock, ye mighty Washington wives, and despair.” And then the First Lady turned out to be wearing the very same dress. Short of some intimate item of clothing or one’s drunken partner falling down, this is the worst fashion solecism that it is possible to commit. Laura Bush took an executive decision, and went upstairs to change.

But what is the moral? There is no embarrassment when the gents all turn out wearing the same kit, whether penguin or walrus. But if a lady plays competitive fashion, she should not wear red. The uncharitable will say either that she is a racing certainty, or that she is trying to look younger than her years. Once upon a time, the designer of The Empress’s New Clothes for Jacqueline Kennedy was exclusive. But globalisation has infected the rag trade’s finest purveyors.

Perhaps invitations should specify the dress code for women as well as men: “Black tie: red dress at your Schiaperil.” The internet will solve this problem. You will be able to find out what others are wearing, as you can already book your preferred seat on an aeroplane. But until that day, there is a lot to be said for the British tradition of school uniform. When everybody wears the same, then nobody’s behind in the game.