[Jack12]

Here's what worked for me.

It's to do with the type of editor you, or your usergroup using, basically there are 2 editors in vbulletin. Standard and WYSIWYG.

I did have a quick look and couldn't find the stylevar that handled either of these font colors, so I added 2 lines of code to my additional.css template.

For the standard area:

.editor_textbox textarea, .editor_textbox iframe { color:#FFFFFF; }

And for the wysiwyg area:

.wysiwyg { color:#FFFFFF; }

The colour is white, however change "FFFFFF" to whatever colour you want the text to be.