http://shop.nordstrom.com/s/boss-hugo-boss-dulasa-elbow-sleeve-sheath-dress/3716812?cm_cat=datafeed&cm_ite=boss_hugo_boss_'dulasa'_elbow_sleeve_sheath_dress:815365&cm_pla=dresses:women:dress&cm_ven=Linkshare&siteId=Hy3bqNL2jtQ-Z2d2EgVyoLMHbtac1F1ptA or http://www.selfridges.com/en/Womenswear/Dulasa-dress_159-78064228-DULASA50268240/?previewAttribute=Slate+dot or

The first one as it will contrast with your brunette hair :) x

First!

The first one because if you have a medium brown color hair then the dress will bring your hair out more. The second one would just blend with it. Holy expensive dresses

If I had to choose, I would go with the first one if you have darker brunette hair - your hair would sort of "pop" with the rest of the dress. For the second one, if you had lighter brunette hair or hair with streaks of lighter color in it, it would be the same as the above - your hair wouldn't blend in with the dress.