分离纯化蛋白质如何除色素

If the pigment or color is from small molecules,you can pass the protein preparation through size column ( also called gel filtration).If you do not mind about the activity of the protein,you could use some solvents,such as acetone,to precipitate the protein,then centrifuge,and resuspend the protein in your desired solution.
You have to keep it in mind that some protein has pigment,such as hemoglobin,ceruloplasma and others.If you deprive those pigment or colored materials,the protein will not be active any more.
Good luck.

色素一般分子量比较小，用分子筛就可以除去了。