candor vs candidness

candor and candidness both are nouns.

Word	Noun	Adjective	Verb	Adverb
candor	Yes	No	No	No
candidness	Yes	No	No	No

As nouns, candor and candidness are synonyms defined as:

candor and candidness: the quality of being honest and straightforward in attitude and speech

Other synonyms of candor include candour, directness, forthrightness, frankness.

candor (noun)	candidness (noun)
the quality of being honest and straightforward in attitude and speech	the quality of being honest and straightforward in attitude and speech
ability to make judgments free from discrimination or dishonesty