1. Colour of the ball to be used in snowy conditions. Experiment to use an orange ball throughout the 2010/11 FA Cup was abandoned in the first round replays after it was clear that, unless it was snowing, orange balls are incredibly hard to see.
2. Colour of the Dutch national team's shirts, hence the nickname 'Oranje'. Fans are also easily identifiable by a proliferation of orange outerwear, whether it's snowing or not.
3. Traditional foodstuff taken on board at half-time, hence the interval also being known as 'oranges'. Rodney Marsh's England career was (allegedly) cut short when Alf Ramsay told him to give his all for 45 minutes 'because I'm going to pull you off at half time'. Marsh's fateful response: 'Fucking hell boss. All we get at [Manchester] City is a cup of tea and an orange'.