How do you lessen the saturation of a color?

It is when we add other colors, especially black and white that the saturation of colors lessens. When colors are “greyed” down with black and white they become less saturated. However saturation is always relative. If we make a grey with a tiny amount of orange, in addition to black and white we would say it is more saturated than a grey that is only made by mixing black and white together. Black and white have zero saturation, so adding them to other colors lessens the saturation of those colors. You can also reduce saturation with a color's complement. For example, to quickly lessen the saturation of red, add a little green.