officejet 4635 will not print color

I have an officejet 4635 connected via wireless to my MacBook air.  I can print in black without any difficulty, but cannot print in color.  I've taken color cartridge out, replaced it etc. There's no interference, print heads are clean (printer's only a month or 2 old).  I purchsed it to print pictures, but think i might need to return it unless someone has suggestions!  Thanks!