One of the earliest cards was sent in 1415 by Charles, duke of Orleans, to his wife while he was a prisoner in the Tower of London. The card is now preserved in the British Museum. This widely depends on culture. These are the formal meanings in English speaking cultures. Each of these meanings is still used in society today.
White roses are for true love.
Red roses are for passion. Yellow roses are for friendship. Black roses mean farewell. Yellow roses mean friendship. Pink roses mean friendship or sweetheart.