The origin of the choice of "red" to describe Native Americans in English is debated. While related terms were used in anthropological literature as early as the 17th century, labels based on skin-color entered everyday speech around the middle of the 18th century. "At the start of the eighteenth century, Indians and Europeans rarely mentioned the color of each other's skins. By midcentury, remarks about skin color and the categorization of peoples by simple color-coded labels (red, white, black) had become commonplace."