Sometimes the drop-downs work, sometimes they don't.

Which is why you need to learn how to use BBcode accordingly.

For font: [FONT="font_name_here"]text_here[/FONT].

For font size: [SIZE={1, 2, 3, 4, 5, 6, or 7}]text_here[/SIZE].

For font color, you should learn the names/codes that vBullein use. After you've selected the color name/code, you can use color in text: [COLOR="color_name_here]text_here[/COLOR].