Is this Trademark Infringement?

So I stumbled across these shoes on Forever21.com and my first though was...how can Forever 21 make these shoes and not get sued by Christian Louboutin?

Forever 21's Version of Christian Louboutin's Red Sole

Christian Louboutin's Authentic Red Sole

For those of you who don't have the Devil Wears Prada on DVD, hate Sex in the City and can't stand Project Runway, let me just say, Christian Louboutin is the cream of the crop designer of shoes right now. His signature and trademark look always includes a red sole. Watch Oprah lately? Notice the sole of her shoes - they are always red indicating she's wearing Christian Louboutin.

So how is it that Forever 21 can get away with mass producing a red soled shoe? I don't know. But if I was Christian Louboutin's lawyer, I'd be serving some papers to the multi-million dollar label, Forever 21.