Up to a point, I agree “in daily life it’s close enough.” But, I’ve seen more than a few “indigo” submissions that were definitely more like lavender or lilac than a shade of blue; I’ve also seen a plethora of gorgeous purples submitted as indigo and vice versa. Indigo is a dark, pure blue (it’s that shade of blue just bordering the flaming sunset, as darkness overtakes the sky), as opposed to navy, which is a black-blue. As to orange vs. yellow-orange, I would say that the fruit comes in shades ranging from yellow-orange (as most grocery store oranges look) to pure orange (the orange I used to see when we plucked them straight off the tree, fully ripened, in Florida) and red-orange (or the Seville orange color often seen in Spanish paintings, especially from the Renaissance era onwards).

I really think most of the confusion is down to industry marketing. They spend a lot of money researching and then marketing a color name. They intend to make people feel an aesthetic draw toward color names, the same way we inherently feel something about colors. But, my experience is that most people seem to find the names arbitrary and don’t necessarily connect them to the corresponding physical colors.

Actually, the psychology of color is fascinating. I encourage everyone to read a bit about it.