Blue is the colour of the clear sky and the deep sea. It is located between violet and green on the optical spectrum.Surveys in the U.S. and Europe show that blue is the colour most commonly associated with harmony, faithfulness, confidence, distance, infinity, the imagination, cold, and sometimes with sadness. In U.S. and European public opinion polls it is overwhelmingly the most popular colour, chosen by almost half of both men and women as their favourite colour.