Oops, that MIDI linked to by Sorcha appears to be the same as BLACKCO2, the tune in the DT to BLACK IS THE COLOUR (2). If that is an accurate transcription I apologise, but it's like nothing I've ever heard sung.

(The other tune, TUNE FILE: BLACKCOL with BLACK IS THE COLOR OF MY TRUE LOVE'S HAIR in the DT is the 'arrangement' by John Jacob Niles)

I could do the tune I know to go with the words I posted, if it's nowhere else to be found.