Yeah, colors can be objectively determined by measuring the wavelength of light that is reflected by the object.

Quote Originally Posted by PuPu
"This band is bad" vs. "This band is not bad"

This works the same way. Both of these opinions can't be not wrong. One of them has to be wrong.
Um... I would agree if it's the same person saying that, but if it's two different people, then they can have two definitions of "bad," neither of which can demonstrably "wrong" by an objective standard.