Dying to get my hair colored

Hey girls! I am 18 weeks 3 days, and I haven't had my hair done since months before I found out I was pregnant. I had an appointment scheduled for the week after I found out and I was too nervous and cancelled. Now that I am well into the second trimester, I was wondering if it's any safer to get my hair colored? I have heard some people do it throughout pregnancy, some people say not at all, some people say just not in the first trimester, and I just feel so lost. Any info on the subject would make me feel much better! Thank you!