One of my guilty pleasures of the last year was Spartacus: Blood and Sand on Starz. Lucy Lawless's character, the crafty Lucretia, was almost always shown in completely wrong colors to emphasize her phoniness.
Here's Lucy Lawless in good colors (as virtuous Xena, Warrior Princess):
The difference, and the reason Batiatus appears in his correct colors, is that he is sincerely insincere. He is a fearless, plotting, power-hungry schemer inside and out, and he revels in it. No weakness, no self-doubt. He's totally centered in himself.
Lucretia, though, worries. She frets. She's not happy. She wants something more... it's not clear what.
(A clue: just about the only time she looks halfway real is in a scene at the end of the season, when she's lying in bed, having just discovered she's pregnant. Hair's still wrong, but the ivory robe, soft light & natural makeup create a less artificial effect:)
So in addition to the contrast between these crafty characters and the virtuous characters in the series, the narrative is enhanced by dramatic contrast between husband and wife. Batiatus is strong, centered and authentic; Lucretia is scattered and false. Their colors communicate this to us, probably without us realizing it.