A Peek into Red's Past
Red, rouge, rot, rosso are all terms that mean pretty much the same.
Interestingly, most of the terms meaning red, were derived from the Sanskrit word rudhira, meaning 'blood'.
From this relation to blood (and hence to life, danger, female, etc.), the various symbolisms associated with the colour red arise - hospitals/medicine/aid, war, woman/goddesses/feminine entity.
The colour red, at one point of time, was an extremely elevated colour. Almost as regal and royal as 'Purple' itself - purple that was used only in the king's robes and royal decor. The term scarlet, was the name of a particular coloured cloth that was available in 13th century England, and because of its high cost, 'scarlet' became the next 'purple'.
(trivia from Colour and Meaning by John Gage)
From being such an exclusive and royal colour, today red is one of the most excessively used colours in the contemporary world - seen most widely in the logos for fast food, telecom, banks, colas, and apparel brands to name a few.