whiteness vs frostiness

whiteness and frostiness both are nouns.

Word	Noun	Adjective	Verb	Adverb
whiteness	Yes	No	No	No
frostiness	Yes	No	No	No

As nouns, frostiness is a hyponym of whiteness; that is, frostiness is a word with a more specific, narrower meaning than whiteness:

whiteness: the quality or state of the achromatic color of greatest lightness (bearing the least resemblance to black)
frostiness: a silvery-white color

Other hyponyms of whiteness include alabaster, bleach, bone, ivory, off-white, pearl, chalk, hoariness.

whiteness (noun)	frostiness (noun)
the quality or state of the achromatic color of greatest lightness (bearing the least resemblance to black)	coldness as evidenced by frost
lightness or fairness of complexion	a silvery-white color
the state of being unsullied by sin or moral wrong; lacking a knowledge of evil