How is my printer printing BLUE without blue ink?

You actually believe what printer cartridges say?
I can't tell you how hard my mind is laughing right now.

Sounds to me like you've put a blue ink cartridge in. That or your print heads need cleaning.

They usually don't fit for the wrong color cartridge. How did you "trick" it?

The point is not what the printer cartridge says, it is that the printer is printing BLUE with NO BLUE INK and has now printed about 70 pages of full text in BLUE plus pictures with only black, yellow, and the pink/red color. How?

I trippled checked and had 2 others that were stumped look that the cartridge in the blue spot is actually black. It is the black number and the store packaging and labels are black. I even took it out and can see black on the dispenser end. It has now printed over 70 full pages of text in blue and pictures in blue. Strange.

You are right. Imagine that. H.P. makes the cartridges to only fit the color slots they want to force and sell to you. I saw the bottom plastic of the different cartridges is grooved different to only silde into the proper slot. I needed to print black and was stopped unless I made a 30 mile round trip to buy more blue. Discovering the grooves in the cartridges I got scissors out & notched out the plastic, it was only a small section at the end of the cartridge, to get it to slide in. Then the printer said that it was not an authentic or a broken cartridge. Imagine that. HP even put a small metal chip on the cartridge that is a coded electronic chip to trigger the color cartridge. The chip is on the cap section of the ink cartridges. I took off the blue and black caps and switched the caps. The caps only have configuring holes in them to slide over the ink dispenser so no ink was on the cap to carry over blue to the black cartridge. Yes I was in a jam and determined to outsmart my printer and HP. The qeek squad team all laughed at the devices HP put in place including the color chip that I switched. They still can not figure out how I am getting so many full text pages and even pictures of blue. Thanks for the imput. Still stummped.