HP Color Laserjet CP3505n - printing in colour. Sometimes.

[Southmeader]

This is a bit of an old chestnut but was there ever a solution to the problem that a number of people had with HP laserjet printers sporadically refusing to print in colour? My Dell XPS7100 running Windows 10-64 bit will sometimes not send colour data to the HP and I get greyscale. Running the HP demo on the printer gives me colour, as do the printer reports. Driver is current. Driving me mad!