You would need to get the css for the color added inline or attach an absolute path to your .css file to the email so that it can be referenced in the body.
I am adding color from the HTML Editor toolbar. At first I didn't think any HTML code was passing then I tried underline and stirke through and that was working, so it seem that just the color is not working. I am on a basic website that I am just starting Webassist did not load any .css files. HTML editor is the only extention I have on this site so far.
Do you know if UE works with Amazon SES yet?