You need to have Foomatic-RIP and Ghostscript installed. You can find links to installers on this page: http://www.linuxfoundation.org/collaborate/workgroups/openprinting/macosx/pxlmono (alternatively you can install ghostscript using brew with ‘brew install ghostscript’). There is a pxlmono download on that page which contains loads of PPD files for all sorts of printers, but none of them support colour.
Once the dependencies are installed, you can use pxlcolor to generate a PPD file on this page for the printer, or generate a Generic PCL 6/PCL XL Printer PPD file (attached), which allows you to print with colour. http://www.openprinting.org/driver/pxlcolor
Set the printer up using Cups. To do this you need to enable the web interface by running this from a Terminal prompt: cupsctl WebInterface=yes
You can then browse Cups on http://localhost:631/printers/
Choose to add a printer, and specify LPD as the network protocol, using the IP address as the hostname and ‘lp’ as the queue name. So something like lpd://192.168.103.229/lp
When prompted to specify the printer, you can choose the generated PPD file from your disk.
You can then set the defaults using Cups to print in colour.
Ta-da!