One of the great differences between North America and England is the choice of the flavour that lies behind the mysterious colour purple.
Grape flavouring is a rare thing in Britain. There is no Grape Koolaid. But, there is Ribena, the purply nectar of the gods.
The colour purple is retained to signify the One True Pleasure that is known as black currant. Ah, the delicious delights of blackcurrant sorbets, blackcurrant jam, blackcurrant fruitgums...
The only substance that should be grape flavoured is wine.