During Stella McCartney's Green Carpet Challenge, two distinct stories were told—one of delicate flowers and lace and the other of strong and pronounced color blocking. Both stories were united by the look created by Aveda Global Creative Director, Antoinette Beenders. "This is the look of a strong London girl," notes Antoinette. "It's severe, but soft. The front is masculine-chic, with a geometric squareness to it. In contrast, the back is polished and delicate. It's editorial, yet wearable. Stella McCarthy is creating a force of sustainable and ethical leadership in fashion, and as Aveda itself was…