The natural haematochrome extracted from plum skin is a kind of safe and non - poisonous colorant.

从李子皮中提取天然红色素是全无毒食用色素。

If the hair graying is inreversible, hair colorant is the main choice for the masking of hair color change.

在无法逆转头发变灰情况下，着色剂是恢复头发颜色主要方法。

This article describes the use of organic colorants as the optical recording media, such as polymethine cyanine, phthalocyanine, naphthocquinone and photochromic compounds.

了用作光学记录质有机染料,如多甲川菁、酞菁、荼醌以及光变色化合物等。