I think they need more styles for the different parts of where they appear because it looks like it would be hard to get a color that works well.
Example...
http://community.mybb.com/thread-74841.html
It shows up fine in the breadcrumb and in the thread listing but at the title of the thread it self you can't read it.
Yeah I bought this up in the suggestions forum... what looks good on the forum display looks bad on the thead, and vice versa.
I'll have a play with some different colours.
This has now been changed.
Note that it won't appear here just yet but when you all upgrade to 1.6 it'll show the plain text version in this location, but the styled version will still show in the navigation and on the forum display.

I think Italic too might work.
I just reviewed Mybb.com code for thread prefixes. Why doesn't it have it's own CSS definition? WTF that's a total fail. Seriously a really bad oversight.
(2010-08-02, 06:09 PM)labrocca Wrote: [ -> ]I think Italic too might work.
I just reviewed Mybb.com code for thread prefixes. Why doesn't it have it's own CSS definition? WTF that's a total fail. Seriously a really bad oversight.
<span style="color: #555555; font-weight: bold;">
Well that's lovely.
That's just the CSS to style the prefix itself. There's a plain text version and an HTML version where you put your CSS, individual to each one.