Football's latest card will be shown at the Copa America after a rule change

Fans watching this summer's Copa America could soon see the latest card brandished in football.

South American football's governing body CONMEBOL have passed a rule ahead of the tournament in the United States, which will introduce a pink card.

A pink card will be part of a system which could see a team granted an additional substitute in matches.

Referees will brandish the card if they are notified of a team making a substitute as a result of a concussion or head injury.

The card will confirm both sides will have an additional substitute as part of the rule, after football's lawmakers the International Football Association Board (IFAB) approved permanent concussion substitutions back in March.

Pink cards are among the latest to be shown in the game, with several new colours introduced in recent years.

Fans are used to red and yellow cards for fouls and misdemeanors during a match, having been implemented over 50 years ago at the 1970 World Cup.

Earlier this year, IFAB planned to approve a controversial proposal to give referees blue cards to use in sin-bin trials.

Referees would have had the power to order players to the sin-bin for acts of dissent against officials and cynical fouls.

Players would have been warned that two blue-card offences, or a combination of yellow and blue, would add up to a red card and dismissal.

The plans were ultimately shelved amid a widespread backlash to their introduction, although sin bin trials have continued at grassroots level.

A white card had initially been proposed by former UEFA president Michel Platini, but these have been used for a different reason in Portugal.

White cards have been used as part of an initiative in Portugal to recognise and encourage fair play and was designed to 'improve