HTML Email Colour Tags

Question

Hello all
I am writing a Marketing email program so we can email news letters and the like to customer listed in our database.
One part of the application is a email templates page. On this there is a tabpage. Tab1 has a textbox and teb2 has a browser window.
The user pastes/write HTML code in to the text box and it displays the formatted email/html in the browsers window.
The users just want to edit the text from time to time and within VS.NET and TEXPAD the html code is colour coded depending on the html tags.
I guess this can not be done in my textbox1 but can it be done in a rictextbox and text_change event?
I hope I have made sense!!
thanks
Atr