Not sure if anyone has done this yet, if so I have not seen it this advanced. I worked up this code to get a colored text box with several options.
-header background color
-header text color
-text body background color
-text body text color
-change alignment of header and body independently
-change the padding of the text
-change font style of header and body independently
Just paste the following code into a new text box widget and edit the code to fit your needs. Hope this is something useful for you!