Pharaoh cuttlefish they can show a mottled white and brown color, with a center circle of brown. The mechanism for color is the same in the Pharaoh cuttlefish as it is in other cuttlefish. This colour-changing function is produced by groups of red, yellow, brown, and black pigmented chromatophores above a layer of reflective blue and green tinted iridophores and leucophores, with up to 200 of these specialized pigment cells per square millimeter. These sacs of color are controlled by rings of muscle around the sac. The cuttlefish expands and contracts these muscle rings in order to show different colors. It is
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