Check if your printer options has a "print in B&W" setting. Maybe its
switched on.
Have you tried the "print test page" from the printers properties?
Have you run the maintenance to clean the print heads?
If its no and yes and yes to the above then maybe there's a blockage. Has
the printer been out of use for a while? If so many inkjets will dry out and
cause this type of problem. Check on the makers website for tips on clearing
blockages.