I just thought I would bring this up.
While in the forums, most users just leave their font size and color as default, seeing as most don't take the time to change it every time you post. My idea is that you could pre-set it in the Forum Preferences.
Example: Hello, this is an example post. As you can see, I have manually changed the font itself, the color, and its size.
You don't like to see crazy font all over the page? There could be an option to disable viewing custom user fonts.
Simple. Fun. Consider it.