Evolution of human colour vision lights, which appear to be clear. Other colour perception issues include having trouble distinguishing yellows from reds and violet, lavender and purple from blue. In other cases, objects that reflect both red and blue light may appear to just be blue to these individuals. Deuteranopes, who are missing medium wavelength sensitive cones, are similar to protanopes in that they cannot distinguish between colours in the green-yellow-red part of the electromagnetic spectrum. However, deuteranopes do not suffer from dimming issues. For example, purple colors are not seen as being opposite to other colours in the spectrum but instead appear to be
Blue is the most popular colour, chosen by almost half of both men and women as their favourite colour. The same surveys also showed that blue was the colour most associated with the masculine, just ahead of black, and was also the colour most associated with intelligence, knowledge, calm and concentration. Blue is the colour of light between violet and green on the visible spectrum. Hues of blue include indigo and ultramarine, closer to violet; pure blue, without any mixture of other colours; Cyan, which is midway in the spectrum between blue and green, and the other blue-greens turquoise, teal, and