This Black Bra fits tighter... why is that?

Woman wearing a black bra.

It is a know fact in the lingerie industry that black bras run smaller than lighter colored bras. Why does this happen?

The dyes used to color black bras shrink the material just the slightest bit, and when you’re talking about a garment that needs to be an almost perfect fit, this is really noticeable.

Some say that black fabric will loosen to its regular size with washing. I'm unsure if this is true or a myth.