that's the culprit! black printhead!
+1 to your print being purple because your printhead isn't laying the black ink on top of the magenta ink properly to make the color your profile is specifying.
printing at 4pass/8pass may reflect differences because your printhead will use different lines of nozzles during the print at different spots in each.
not 100% certain if its a dying head or just massively clogged nozzles...
do an overnight nozzle wash and post another pic of the test print. my jv3 has a 99min max, but I just power-down the printer and unplug it from the wall for the night (after setting the nozzle wash cycle), won't hurt it one bit.
also, do you have foam swabs? not cotton-tipped ones, but the square foam ones. I've restored some nasty clogs by taking a foam cleaning swab that's soaked with cleaning solution and gave the bottom of the printhead a "lick" prior to setting my wash. Don't scrub, don't put pressure on it, but one clean motion across the printhead like your wiper does and then I set an overnight wash and my nozzles were firing 100% in the morning.
