Source : Webster's Revised Unabridged Dictionary (1913)

Redness \Red"ness\, n. [AS. re['a]dness. See {Red}.]
   The quality or state of being red; red color.

Source : WordNet®

redness
     n 1: a response of body tissues to injury or irritation;
          characterized by pain and swelling and redness and heat
          [syn: {inflammation}, {rubor}]
     2: the quality or state of the chromatic color resembling the
        hue of blood [syn: {red}]