Achromatic colors

Achromatic colors possess no dominant hue — they absorb or reflect all light wavelengths equally. White, black, and all shades of gray are achromatic colors. 

White reflects all light and absorbs none, while black is the opposite (gray reflects all light wavelengths equally, to varying degrees). They lack hue and temperature and have only one property — value, which is the relative lightness or darkness of a color.