I think he probably isn't wearing lipstick for the simple reason that in the Heian period, make-up was very basic. Rise paint for whitening the face, charcoal (mixed in a oil based something) to draw eye brows and some sort of red juice for lips? And all that only for the women.

What is more interesting is those earstuds he's wearing.
That was not a Heian style. In fact, earrings are not even a Japanese style (throughout the ages).
So where did they come from?