candor (n.)

"openness of mind, impartiality, frankness, freedom from reserve or disguise," c. 1600, from Latin candor "purity, openness," originally "whiteness, brightness, radiance," from candere "to shine, to be white" (from PIE root *kand- "to shine"). Borrowed earlier in English (c. 1500) with the Latin literal sense "extreme whiteness."