[Groff] Colors with gropdf

[Robert Marks]

I have recently had to embed a PDF image in a groff document and so have
been using
groff -Tpdf
to do so.
But I find that my \m[red] etc color commands are not recognised (and there
are error messages..
Some work on Google led me to the Ubuntu gropdf manual, which states:

 The  default  color  for  \m and \M is black; for colors defined in the
       ‘rgb’  color  space  setrgbcolor  is  used,  for   ‘cmy’   and
‘cmyk’
       setcmykcolor,  and  for  ‘gray’  setgray.   Note that setcmykcolor
is a
       PostScript LanguageLevel 2 command and thus not available on some
older
       printers.

Searching for setrgbcolor tells me that it's a PS commend to be used:
.ds RED \X'ps: exec 1 0 0 setrgbcolor'
and then referring to \*[RED] to change the color from black, say.

But there is no change (and no error messages). Using groff 1.22.2

Any advice on using color in gropdf or groff -Tpdf ?

Thanks,

Bob

-- 
http://www.agsm.edu.au/bobm
0407665644