black-gray-white
Colors with minimum chromaticity, ranging from black to white and including shades of gray.
Black/gray/white is a range of colors without any clearly perceptible hue; the class includes black, white, and a wide variety of gray shades. Warm and cool shades of gray, which have a faint hint of color, are also included because the component color is not easily recognizable.
Colors with recognizable hue, which approximate black or white because of their darkness or lightness, are not included unless the hue is very difficult to discern in good lighting.
A faint warm or cool tint is permitted when it is not readily recognizable as a separate hue. Very pale or dark colors with clearly discernible hue remain outside this group, even when they approach white or black.