Auxochroms

This word is derived from a Greek word auxanein means to increase/intensify and chroma means color. So, the groups which intensify the color is called auxochrome. It also increases the affinity for textile fibers.

Example:

1.      Hydroxyl group (-OH).

2.      Amino group (-NH₂).

3.      Methyl group (-NH-CH₃).

4.      Nitrate group (-NO₃) etc.