Kinda. There's a singularity in the math. The problem is that hue is defined as an angle and saturation is defined as distance from the center, but there's no consistent way to define a direction for the origin. Black and white have the same problem because they're also desaturated.

> And if you buy a forest motif, people will be upset if it's pink. That's just doing a tie-dye wrong, not a rebuke of whether it's a color at all.

I'm not arguing that it's not a color, just that it doesn't belong in all gradients!