How did the yellow and red cards in football come about?

KohakuThe yellow and red cards a referee holds up high. There is something that gave a hint for those colors, they say.

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The cards were devised by English referee Ken Aston. He is said to have taken the idea from traffic lights, as a signal that gets across without a shared language. They were first used at the 1970 World Cup. Yellow is a caution and red is a sending-off.

A referee's arm raised high holding a yellow card — A yellow card signals a caution, and a red card signals a sending-off.Photo: Steindy (talk) 00:38, 30 September 2015 (UTC) / CC BY-SA 3.0 (cropped) / Wikimedia Commons

Yellow is a caution, red is a sending-off

Referees in football (soccer) show cards to tell players about a caution or a sending-off. Under today's rules, a yellow card means a caution and a red card means a sending-off. Cards may be shown only to players, substitutes, and team officials, among others.

The language barrier was the spark

The cards are said to have been the idea of English referee Ken Aston. Aston was in charge of the referees at the 1966 World Cup. At that tournament, there was a match in which it was hard for a player to tell whether he had received a caution. Players and referees from different countries speaking different languages found it hard to get their meaning across, and that had become a problem.

KohakuWhen languages differ, getting your meaning across is difficult, isn't it?

Traffic light colors gave the hint

The inspiration is said to have been a traffic light. After a match, Aston stopped his car at a traffic light on Kensington High Street in London, and it is said that the idea of signalling with colors came to him then. Yellow means "take care" and red means "stop," so the meaning gets across even without a shared language. This idea led to yellow for a caution and red for a sending-off.

First seen at the 1970 World Cup

The cards were first used at the 1970 World Cup, held in Mexico. However, it is reported that no red card was shown at that tournament. The first red card at a World Cup was shown at the 1974 tournament, when a Chilean player was sent off.

Figure: The colors of the cards and what they mean

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Before the cards, referees are said to have sometimes used exaggerated gestures to get past language differences.
Under today's rules, cards may be shown only to players, substitutes, substituted players and team officials.

KohakuAs a signal that works even without a shared language, the cautions and sending-offs of the cards remain in today's rules.

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What inspired the card colors?

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Flag colors
Traffic light colors
Referee uniform colors

Traffic light colors Referee Ken Aston is said to have taken the idea from traffic lights, as a signal that gets across without a shared language.

Sources

How the 1966 World Cup Led to the Invention of Yellow and Red CardsHISTORY
Colchester-born referee Ken Aston invented cards in footballGazette (Colchester)
The dirty look and the traffic lights that gave birth to yellow and red cardsThese Football Times
Law 12 - Fouls and MisconductIFAB (International Football Association Board)

This article was written after checking the sources above as of 2026-10-03. Explanations may change as research progresses. Photo credits are shown below each photo.