Which of the following is not a chromophore?

-NH2 group is not a chromophore but is an auxochromeChromophore is that part of the molecule which when exposed to visible light will absorb and reflect a certain color. Auxochrome is a group of atoms which is functional and has the capability to alter the capacity of the chromophore to reflect colors. Azobenzene is an example of a dye which contains a chromophore. Examples of auxochrome groups are -COOH,-SO3H, -OH, and -NH3.