As PAHU has indicated you are using an incorrect driver that is intended for a B/W laser printer. It simply appears by default because no driver is identified as available or you haven't selected the proper driver.
Delete the existing printer from Print & Fax, then click on the [+] button. Click on the Default icon in the toolbar. If your printer appears in the list then select it. Then select the option to Select Driver from the drop down menu. Locate a driver for your printer, select it, click on the Add button.
If no driver is listed then install the recent HP drivers update or download a compatible driver from HP. If there is no SL driver available then try the most recent Leopard driver which may work.