Yes, COMPLEXION is a Scrabble word!

Letter values in Scrabble US: C 3, O 1, M 3, P 3, L 1, E 1, X 8, I 1, O 1, N 1.

Is it a valid word?

COMPLEXION is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the coloring of a person's face
a combination that results from coupling or interlinking
a point of view or general attitude or inclination
texture and appearance of the skin of the face
(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

Also: skin color, skin colour.