the current code doesn't have such functionality but it can be added as long as you know what you're doing (but not exactly the way skype is doing it).
anyways, it requires a real web host where you can upload the file to and then your friend will receive a private link so he can click to download it.
I'm not getting what you're saying, but if you downloaded the latest code you'll see that all of styling properties can be found in the cb_style.css and you can change whatever property you want from there.
<p style="color:red;"> hello</p>
and then click on send but the color didn't changed
Hope it helps.