I know when Renderosity changed it's colors, the fractal people all were outraged that the black background disappeared. I do think that most fractals look best against a black background, but obviously there will be some few that use a slightly different black background themselves and will not look really good. At that point, I think the artist should arrange to do what he/she thinks is best for their own image, or even not post that particular one.

Fractals will always amaze me!