I suppose that these qualify as diaphanous. (CAUTION! the title of this image is
0238 Arachnophobia. If you've got it, don't look at the original! Don't say I didn't warn you...)
Of course the combination of a rainbow and water spray is also diaphanous, and far less likely to freak people out unless they have spectrum-phobia or are being haunted by the ghost of Isaac Newton:
And finally, of course, we have the diaphanous mist: