If you have recently moved to Mac from Windows and you want keep on using your old HP color printers, you are having some issue for sure.
The most drivers present in OSX are not compatible with yours and so you are only able to print in black and white.
To simply solve this problem, just install he HPijs driver from Linux Foundation. Just go to this site:
and install all the three package:
Now you have only to switch on your printer and all your colors prints are there!