I hope my question does not seem trivial or insensitive to those of you with pain or discomfort. I have been taking hydroxy for three weeks now and so far thankfully no side effects other than tiredness. I have a smattering of grey hair and get by with a touch up at the hairdressers about every three months. I am a little concerned re using colour on my hair now. Are there certain types of colour that are safe as I know many are linked to cancer? I may have to take the plunge and go gracefully grey.