The Collaborative International Dictionary of English v.0.48:

Complexion \Com*plex"ion\ (k[o^]m*pl[e^]k"sh[u^]n), n. [F.
   complexion, fr. L. complexio. See Complex, a.]
   1. The state of being complex; complexity. [Obs.]
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            Though the terms of propositions may be complex, yet
            . . . it is properly called a simple syllogism,
            since the complexion does not belong to the
            syllogistic form of it.               --I. Watts.
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   2. A combination; a complex. [Archaic]
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            This paragraph is . . . a complexion of sophisms.
                                                  --Coleridge.
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   3. The bodily constitution; the temperament; habitude, or
      natural disposition; character; nature. [Obs.]
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            If his complexion incline him to melancholy.
                                                  --Milton.
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            It is the complexion of them all to leave the dam.
                                                  --Shak.
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   4. The color or hue of the skin, esp. of the face.
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            Tall was her stature, her complexion dark.
                                                  --Wordsworth.
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            Between the pale complexion of true love,
            And the red glow of scorn and proud disdain. --Shak.
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   5. The general appearance or aspect; as, the complexion of
      the sky; the complexion of the news.
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WordNet (r) 3.0 (2006):

complexion
    n 1: the coloring of a person's face [syn: complexion, skin
         color, skin colour]
    2: a combination that results from coupling or interlinking;
       "diphthongs are complexions of vowels"
    3: a point of view or general attitude or inclination; "he
       altered the complexion of his times"; "a liberal political
       complexion"
    4: texture and appearance of the skin of the face
    5: (obsolete) a combination of elements (of dryness and warmth
       or of the four humors) that was once believed to determine a
       person's health and temperament
    v 1: give a certain color to; "The setting sun complexioned the
         hills"

Moby Thesaurus II by Grady Ward, 1.0:

121 Moby Thesaurus words for "complexion":
   achromatism, air, ambiversion, bearing, body-build, brand, brow,
   carriage, cast, cast of countenance, character, characteristic,
   characteristics, chromatism, chromism, color, color balance,
   color harmony, color scheme, coloration, coloring, composition,
   constituents, constitution, countenance, crasis,
   cycloid personality, cyclothymia, decorator color, demeanor,
   dharma, diathesis, disposition, ectomorphism, ectomorphy,
   endomorphism, endomorphy, ethos, extroversion, extrovertedness,
   face, facial appearance, fashion, favor, feature, features, fiber,
   form, frame, garb, genius, grain, guise, habit, hue, humor, humors,
   ilk, individualism, individuality, ingoingness, introversion,
   introvertedness, key, kind, lineaments, lines, looks, makeup,
   manner, mesomorphism, mesomorphy, mien, mode, mold, natural color,
   nature, other-directedness, outgoingness, pallor, personality,
   personality tendency, physiognomy, physique, port, posture,
   presence, property, quality, schizoid personality, schizothymia,
   shade, shape, skin color, somatotype, sort, spirit, stamp, stance,
   streak, stripe, style, suchness, syntony, system, temper,
   temperament, tendency, tenor, tinct, tincture, tinge, tint, tone,
   traits, turn, type, undercolor, vein, visage, way