Madame de La Fayette

"The King's colours were white and black, which he always wore in honour of the Duchess of Valentinois, who was a widow. The Duke of Ferrara and his retinue had yellow and red. Monsieur de Guise's carnation and white. It was not known at first for what reason he wore those colours, but it was soon remembered that they were the colours of a beautiful young lady whom he had been in love with, while she was a maid, and whom he yet loved though he durst not show it. The Duke de Nemours had yellow and black; why he had them could not be found out: Madam de Cleves only knew the reason of it; she remembered to have said before him she loved yellow, and that she was sorry her complexion did not suit that colour. As for the Duke, he thought he might take that colour without any indiscretion, since not being worn by Madam de Cleves it could not be suspected to be hers."