my WAG, which should be corrected if it is ignorant, is that the high cost of color printouts comes from the need to use several types of ink or toner. So suppose we wanted to do “green and white” printing instead of “black and white”. Or substitute whatever color that is a primary color under existing printing technology instead of green. Would the cost of printing be as low as color black printing?
It might be only if the copier was dedicated to printing that single color and the cost of that color toner was the same as black. In fact, neither one is generally the case, so the price for color would be somewhat higher.
As you must know, green in either an inkjet or a laser color copier is actually produced by using at least two colors of toner or ink, but often four colors to reproduce the specific shade.
The first color copier I used, though, was in the mid-1980s and it was actually a single color copier that had interchangeable toner cartridges. You could remove the black cartridge and put in a green one for green printing or a red one for red printing.
Since the default, most frequently used color was black, extra was charged for color because it entailed changing cartridges.
Even in print shops running ink on presses, black ink was always cheaper because, again, it was used most frequent and was generally on the press. Use of another color required washing up the press to a completely clean state and putting colored ink on. (To go back to black, one didn’t even need to wash as well, because the black ink generally obliterated any traces of color ink on the rollers.)
And since black ink and black toner are produced and purchased in far greater quantities, they cost less.
got it, makes sense.