Language Barriers Led To Red And Yellow Cards In Football

I've just been watching the Denmark v England international football match and the coverage on TV mentioned that red and yellow cards were introduced in football to overcome language barriers. Apparently the idea was invented by British referee Ken Aston during the 1966 FIFA World Cup, after a game between Argentina and England at Wembley Stadium when cautions were not understood. The story goes that on the way home, Aston passed through traffic lights - and yes, they were red and yellow... From that point the concept of red and yellow cards were born. It took a while to get the system up and running, but they were used in the 1970 FIFA World Cup in Mexico.