If you do something that may or may not make another user scared, uncomfortable, angry, you will be punished. This includes things that are generally looked down upon by society, like incest, rape, murder, terrorism, etc. If you are unsure, don't do it. If you mean it as a joke, say so. You will not be banned for joking unless it goes too far.
Also look at website rules on Rule #1 for more things against this.
You may not take another person's chat color (Unless that color be the default one in the chat). You must find your own. There are about a bazillion colors out there.
Three strike and you are gone. For good. Break a rule, you may get a strike, it depends on the seriousness. You will be warned, clearly. You get three strikes, you are gone, not just from chat. The whole site. Period.