When we use the phrase ‘an orange card’, we believe a tackle is between a yellow card and a red card. The tackle is bad and could be a red, but it could also be a yellow. It means the decision by the referee, whether it was yellow or red, was a difficult or unclear one.
Example:
“Even Kloppa€™s opposite number, Bournemouth boss Andoni Iraola, admitted it (the tackle) was a soft decision to send off Mac Allister. He said: ‘I dona€™t know. In real life, it did not look like a red card. It was more an orange (card)!a€™ (allfootballapp.com)
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