Print parameter in UNIX for Black/White print

Hi there,

We just upgraded the machine to VersaLink C7025. In windows sserver, I could easily enable the setting to print black and white only.

Our Oracle EBS is running on HP Unix system. How can I set the parameters in Oracle printer driver so that the documents can only be printed in black and white as well?

I tried the following parameters but none of them worked.
-oColorModel=KGray
-oColorModel=Gray
-oColorModel=Black

Thank you in advance.