Over the past few months, I've been running processing variations through M.I.T.'s Large Scale Image Memorability project demo. I almost hate to admit it, but I consistently agree with LaMem's relative ranking. In general, full color scores higher than B&W, but there are surprises, like the sepia wash version here.
model: Anne Merriman, Cosmopolitan Models (http://www.cosmopolitanpromotionalmodels.com/looking-4-a-model.php?action=modelprofile&from_search=1&model_id=15117)
hair and makeup: Sara Young at Serenity Studios
Large Scale Image Memorability Project (http://memorability.csail.mit.edu/index.html)