Be candid but not too candid.

Merriam-Webster provides four definitions of the word candor, They are: (1) whiteness, brilliance; (2) freedom from prejudice or malice; (3) kindliness; and (4) unreserved, honest, or sincere expression.  The first and third definitions are described as obsolete and archaic, respectively. In other words, no one means the first or third definitions when they use candor in a sentence. The third definition is not discussed in Garner's Modern American Usuage and if anyone ever meant kindliness when they used the word candor in communicating with me, I am unaware of it. The fourth definition is the one with which most people are familiar.

The example Merriam-Webster uses for the fourth definition is a quote from Aldous Huxley, "the candor with which he acknowledged a weakness in his own case." It is kind of amusing that the example mentions a weak case because a lawyer offering an opinion on their case can get into all kinds of trouble.