It needs to be more business-like, yet retain the black theme look. Anyway, I was thinking some photo-type logo might do the trick. Anyway, black is normally associated with black-hat SEO (illegal SEO) but that's not the theme of my forum.
A business theme is usually something light.
Dark themes are usually used for gaming sites, etc.
I couldn't really say how to make a dark business theme, sorry.
I don't really associate it with blackhat SEO though.
I do personally prefer dark themes though, light themes can be sort of blinding and maybe a little sterile. You do have to keep in mind that it really depends on the person. Some people like dark themes. Some like light themes. Some sites do both.
As I mentioned, black-hat SEO uses black well and I've seen a few other webmaster ones that are black. Anyway, the site is called biz, but is also a webmaster one - or you could say it's one and the same.