No one knows when we started using colour, but we think that ancient cultures may have used colours to symbolize specific things. Research shows us that each culture had a different system for colour use. In other words, the people chose Nk hat the colours represented- blue in one culture could mean the opposite in another. Research suggests that over the years, we have learnt to recognize various colours as a warning. If a primitive man cut his hand and saw his blood, the red colour truly represented danger-it told him to do something about it or he could die. On the other hand, blue or green colour has a sort of healing. effect and helps people reduce their stresses. But the same person 7 would not eat meat if it was blue or green- something tells us that green or blue meat is bad. This is an experiment you can try for yourself with food colouring. Try serving a meal to your friends with the potatoes or rice coloured blue. You know that the food is harmless. but your guests will probably not eat it. And when they refuse the food, they are using a universal ability that humans have developed over thousands or years.