Hacker News Reader

Black is the only non-color when working with additive primaries (RGB, light).

Black is the presence of all colors when working with subtractive primaries (RYB/CMYK, pigment).

If you mix pigments of all colors you wont get black, you will probably get some kind of brown. Thats why you need the K in CMYK - you need a specifc black paint, which contains pigment that absorb all colors. But you cant mix colors to get black.

C+M+Y=K in theory, but in practice the pigments are not calibrated precisely enough to be a perfect black when they combine.

I dont think that is true, even in theory. Non-black color pigments absorb some colors but reflect other colors. So even if you mix pigments you get some light reflected, although the color of the light will be mixed.

Just as you cannot mix black, you cannot mix white. However, a color printer can use the white in the paper to create lighter colors.

A color has the color we see because it absorbs all the other colors and only reflects the seen one.

So it's the same soup either way.

Reply on news.ycombinator.com