 <p>You know how to get the RTB.Text vs RTB.Rtf right?</p> <p>Here is some <a href="https://msdn.microsoft.com/en-us/library/system.windows.forms.richtextbox(v=vs.110).aspx" rel="nofollow">documentation</a> you might enjoy (or not).</p> <p>Once you know the difference between those, you get the text, use that to build the rtf string, and then assign that string into the Rtf.</p> <p>To modify the colors in your rtf string, you should check the documentation on how to format text with rtf. <a href="http://www.pindari.com/rtf1.html" rel="nofollow">Here</a> is the first google result I found.</p> <p>Good Luck.</p>