Scientists have been led to believe that not all folks see all the same colours when they look at similar objects.
According to experts, although there is a general consensus that red is the same shade as strawberries, blood and the planet Mars some people could perceive the colour red as another person's blue.
The revelations come after an experiment with monkeys, which suggests that our colour perception is shaped by the outside world but follows no predetermined pattern.
Colour vision scientist Jay Neitz, from the University of Washington, injected a virus into monkey' eyes which enabled them to see red as well as green and yellow.
Remarkably the group of squirrel monkeys were able to make sense of the new information despite their brains not being genetically programmed to respond to red signals.
The result was that just four months later the monkeys could see in full colour for the first time.
As well as allowing colour-blind humans to tell red from green, the innovative technique could restore sight to the blind.
Sufferers of age-related macular degeneration, which is the most common cause of blindness in the elderly, are among the millions who could eventually benefit.
Importantly, the monkeys were injected with a human gene, suggesting the same technique would work on people.
The 2009 findings prompted researchers to investigate what the monkeys were actually seeing and they concluded that there were no predetermined perceptions ascribed to each wavelength.
The scientists now believe that although people's brains tend to behave in the similarly when they are born neurons are not configured to respond to colour in a default way.
The study has been published in Nature.