Hair Color and Medicine and Viviscal

I'm currently taking medicine accutane for my acne and also using my viviscal to grow my hair faster. But I want to color my hair and I did a strand test and I realize the hair color didn’t take. I talked to my hairdresser and she said that antibiotics do delay hair chemical, but she didn't know about accutane or viviscal. Have any one ever worked with hair or in their hair while taking accutane and had a chemical service that didn't work or took longer how much longer? I want to do another strand test but I would like to know how much longer should I wait to check the hair color?

I would appreciate any help regarding this situation.

TIA,
=^.^=Diva
kat_diva@excite.com