Can I refill a printer’s gray tank with a completely different color to increase color gamut?

Setup:

  • Epson 3880
  • 3rd party refillable cartridges
  • Colormunki Photo

Just thinking creatively here.

Is it possible to replace an ink color in an Epson 3880 with a completely different color in order to increase color gamut in the ranges that I typically use in my prints?

For example, I never print B&W and usually print landscapes, so is it possible to replace the LK or LLK and another ink with green and orange inks? (Of course new profiles are needed—I have the Colormunki Photo.) I am concerned that there is something in the firmware of the printer or the driver that makes assumptions as to the general color loaded in each slot.

If it’s possible, how do I make the best choice for which inks to remove?