When finding a present for a friend, pink is for girls and blue is for boys (stereotype). According to a study in 2007(performed by Anya Hurlbert and Yazhu Ling at neuroscientists at Newcastle University), women may be biologically programmed to prefer redder shades while men prefer blue-green shades.
The participants of this experiment were displayed a screen with different colors and were asked to pick their preference. Hurlbert and Ling found that most people prefer blue, but women picked rather reddish-purplish shades while men preferred dark blue-greenish shades.
With these results, Ling surmises that the color preference and discriminating green for red could have evolved from sex-specific labor roles: while men hunted, women gathered so they had to spot ripe berries and fruits. Another speculation was that women were caregivers and had to be sensitive to a child with a disease or so, whose faced could be flushed red.
From this scientists are now thinking that this maybe the reason why a woman’s retina (layer of tissue on eye) is thinner than a man’s. Also, in a woman’s eye there are more photoreceptors than men, which are prone to reddish colors.