For B&W printing, on most enlargers all three C,M,Y are set to zero. What may be confusing is you can adjust the settings for different grades..that said, I am not aware of any dichro head that needs Cyan to ever be set...but have no experience with any head other than Beselar. Check the insert that comes with the paper or check the mfg web site for settings (read as guide line).

Good Luck.