I know you have to go to mail options and there's a choice for signature. I just have a quote for mine, no special colors or anything. But, I'll go and look to see if there's a place to put more than just text. If you're just wanting to do colorful text, that would be easy. Just go to the signature part in mail options and when you're typing your text, just highlight what you want and choose a font, a size and a color for it. If you're wanting to add more, I'm not sure how to do that. I'm going to look right now!