I used what appears to be the only nebula thing that appears in the FRED1 editor. It has options for pattern, color, pitch, bank, and heading. Only other thing I see in the FRED1 editor is a thing for "bitmaps" that is all greyed out and may not work. If you can show me a screen shot of what exactly you are talking about I can tell if it's what I saw. There are only 2 basic kinds of nebula things I know of: Individual nebula bitmaps you place on the background like you do planets, which seems to be FS2 specific, and full nebulas which have an FS1 version and an FS2 version.