title: TextBox with multiple font colors
body: <p>I would like to develop something like a text Editor for Windows Phone but I faced several problems during the design process. What I basically need is a control that not only allows me to type in text but also lets me draw the text in that TextBox in different colors, just like in Microsoft Office for Windows Phone. 
  As far as I know the TextBox control does not support font coloring. I tried using the  tags but unfortunately this does not work. My question now is if there is a way to have a TextBox that lets me color different parts of the text in different colors. I am thinking about creating a custom control but how would I implement such a feature?</p>