In a series of five studies, about 150 heterosexual men (homosexual men and those with red-green color blindness were excluded) rated photographs of women framed in red, white, gray, green, or blue, or with the woman in a red or blue shirt.

CNN: Wearing red may boost your sex appeal

In the U.S., where tastes are different, Hello Kitty can be purple, green or gray.

CNN: PRETTY IN PINK SLUMP

Mongolian spots (technically named congenital dermal melanocytosis) are flat bluish-green, gray or light brown areas where cells called melanocytes have been trapped in a layer of the skin called the dermis.

CNN: What are Mongolian spots?

When students were given creativity tests, those whose test-cover pages had a green background gave more creative answers than those whose pages were white, blue, red or gray.

WSJ: Tactics to Spark Creativity