Did you get an answer to this post?  If not, I have a couple of ideas -
although they may not be v. elegant.  One is to use code to re-set the color
of the form to 'automatic' before printing.  If you do not want to change the
original then create a temporary copy, make the change, print and then delete
the temporary file.  Alternatively, set up a version of the printer(s) set to
print only in black & white.  For example, if your usual printer is something
like  'Color_Printer_A' then set up another version of it named
'Color_Printer_A_BW' with the settings as described above.  You can then
write code to print the form to that printer rather than the color version.

ArchieD