The Collaborative International Dictionary of English v.0.48:

pallor \pal"lor\, n. [L., fr. pallere to be or look pale. See
   Pale, a.]
   Paleness; want of color; pallidity; as, pallor of the
   complexion. --Jer. Taylor.
   [1913 Webster]

WordNet (r) 3.0 (2006):

pallor
    n 1: unnatural lack of color in the skin (as from bruising or
         sickness or emotional distress) [syn: lividness,
         lividity, luridness, paleness, pallidness,
         pallor, wanness, achromasia]

Moby Thesaurus II by Grady Ward, 1.0:

112 Moby Thesaurus words for "pallor":
   Hippocratic face, achromatism, anemia, aridity, ashiness,
   barrenness, bloodlessness, cadaverousness, cast, characterlessness,
   chloranemia, chromatism, chromism, color, color balance,
   color harmony, color scheme, coloration, coloring, colorlessness,
   complexion, corpselikeness, deadliness, deadness, deathlikeness,
   deathliness, deathly hue, deathly pallor, decorator color, dimness,
   dismalness, dragginess, dreariness, dryness, dullness, dustiness,
   eeriness, effeteness, emptiness, etiolation, exsanguination,
   facies Hippocratica, fadedness, faintness, fairness, flatness,
   ghastliness, ghostlikeness, ghostliness, grisliness, gruesomeness,
   haggardness, heaviness, hollowness, hue, hypochromia,
   hypochromic anemia, inanity, inexcitability, insipidity,
   insipidness, jejunity, key, leadenness, lifelessness, lightness,
   lividness, lowness of spirit, luridness, macabreness,
   mask of death, muddiness, natural color, paleness, pallidity,
   pallidness, pastiness, pointlessness, pokiness, ponderousness,
   prison pallor, sallowness, shade, sickliness, sickly hue,
   skin color, slowness, solemnity, spiritlessness, sterility,
   stiffness, stodginess, stuffiness, superficiality, tastelessness,
   tediousness, tinct, tincture, tinge, tint, tone, uncanniness,
   undercolor, unearthliness, uninterestingness, unliveliness,
   vapidity, vapidness, wanness, weakness, weirdness, woodenness