"Color-blindness" Natural Recordings by Native Speakers
Color-blindness is a condition in which a person has difficulty perceiving certain colors. It is usually inherited and occurs when there is a problem with the genes that code for the light-sensitive pigments in the retina. People with color-blindness may have trouble distinguishing between certain colors, such as red and green, and may see the world in shades of gray or with inaccurate color perception.
Colophonite is a rare mineral, consisting of a hydrated calcium carbonate, whose general formula is CaCO3·3H2O. It is usually white or colorless, but may also be blue or brown due to impurities. Colophonite is found in sedimentary rocks, typically in conjunction with other minerals such as calcite, aragonite, and gypsum.