Hello - Let's see if we can get your printing in color again.
First - reinstall your drivers... http://support.hp.com/us-en/drivers/selfservice/HP-Photosmart-Premium-All-in-One-Printer-series---C3/3984414/model/3793675
Hello - Were you able to reinstall your drivers ?
are there any errors showing on the printer itself ?
one of 2 things are happening
either the computer is sending the pictures in gray scale either because of an accidental check mark in the box that says "gray scale" on the options when you print. or because it thought the color was out and put itself into emergency mode where it will still print with no color cartridges.
If the print outs show the complete picture but its all in various shades of gray rather than colors this is what has happened
The other possibility is that it is trying to print in color but the color ink is just not getting to the page. either because of a clogged print head or defective or empty cartridges.
if the printout shows a blank or extremely light black area where a color should be but no color than this is what is happening.
the difference will be that the picture is actually recognizable if it is printing in gray scale like looking at an old black and white tv or a charcoal drawing.
if you can tell me which one it seems to be i can tell you how to fix it.