pallidness vs skin colour

pallidness and skin colour both are nouns.

Word	Noun	Adjective	Verb	Adverb
pallidness	Yes	No	No	No
skin colour	Yes	No	No	No

As nouns, skin colour is a hypernym of pallidness; that is, skin colour is a word with a broader meaning than pallidness:

pallidness: unnatural lack of color in the skin (as from bruising or sickness or emotional distress)
skin colour: the coloring of a person's face

Other hypernyms of pallidness include complexion, skin color.

pallidness (noun)	skin colour (noun)
unnatural lack of color in the skin (as from bruising or sickness or emotional distress)	the coloring of a person's face