The absence of all color should be clear.
clear is transparent and doesn't reflect, emit
or absorb any light, allowing what's beneath/behind to do so ....
percieved color is a function of the light [spectrum] reflected or emitted, and subsequently detected by your eye, which has
cones that detect only 3 colors
black neither reflects nor emits any light, it absorbs it .... black [or very close] can be 'made' by mixing the correct proportions of the
3 subtractive primary colorsit's all in the eye of the beholder .... or beerholder, as the case may be
Bill