Red is mortality...
But of course following the theme of sex and violence, few crossed the boundaries in their art and literature than the Greeks where passion and rape were often paralleled. It's frightening when you think about it, and the thought doesn't have to go so deep. What is this "rape culture" we talk of now measured against Leda & The Swan? The gods saw what they wanted and drunk on power and "passion" they took it.
Rape was passion.
Murder was whimsy, or maybe just a childish tantrum, and they were never held accountable.
And what is a more of a metaphor for mortality than bleeding monthly?
(Except that women don't die monthly which almost creates a Promethean element to the human story. Titanic tragedy yes but mortality not so much.)
But I digress...