Human hair color used in physical anthropology and medicine to determine the shades of hair color. The scale uses the following designations: A (very light blond), B to E (light blond), F to L (blond), M to O (dark blond), P to T (light brown to brown), U to Y (dark brown/black) and Roman numerals I to IV (red) and V to VI (red blond). Brown hair is characterized by higher levels of eumelanin and lower levels of pheomelanin. Of the two types of eumelanin (black and brown), brown-haired people have brown eumelanin; they also usually have medium-thick strands of hair. Brown-haired girls
Linguistic relativity and the color naming debate frequencies corresponding to different colors. The lengths of habituation were measured and found to be longer when the infant was presented with successive hues surrounding a certain focal color than with successive focal colors. This pattern of response is what is expected when the infants are distinguishing between the focal colors, but not distinguishing between successive hues (i.e. different shades of red are all "red" but "blue" and "red" focal colors are different). This is to say that infants respond to different hues of color in much the same way as adults do, demonstrating the presence of color vision at