Bizhub C350 Color Printing Problem - color prints only black and white

I recently installed Konica Minolta Bizhub C350 (which I bought used, so no install disc) on two dell desktops. One runs XP and the other Windows 7, and both were successfully installed. But later I found that none of them print in color, and I only get black and white print outs. If I want anything in color all I get is a blank sheet of paper. Any recommendations as to what might be wrong?

 

sounds like a software error to me, have you got the correct printer driver?
have you tried an olivetti printer driver, as its the same machine

 

or... as you have bought it used, there might be something set in users' settings.

 

C350 driver for windows 7 does not exist yet
down load driver on minolta site for xp in support dicontinued products