This gray color template includes both achromatic and chromatic grays.
From the en.wikipedia.org
The invention of the achromatic lens in 1733 partially corrected color aberrations present in the simple lens and enabled the construction of shorter, more functional refracting telescopes.
From the en.wikipedia.org
Any color that lacks strong chromatic content is said to be unsaturated, achromatic, or near neutral.
From the en.wikipedia.org
Since achromatic vision was the first to evolve it explains why the majority of the population are not affected by black-white color blindness.