printer prints only black and white using airport

All is ok when printer is connected direct to computer USB but only B/W when connected to Airport USB and using a wifi connection.

I have a HP printer connected to my airport express USB and it only prints in black & white. Apple says it's the HP drivers and HP says that printer was not designed to work wireless. However I've found a workaround. Leave your printer switched off then tell your program, Photoshop, Adobe PDF or whatever to print so that gets put into the printer queue now switch your printer on and Voila! your printer produces a perfect colour print. Works everytime for me.