Marianne, I personally love the dress on you. The sleeves are flattering in my opinion because they are elbow length. I love the dress with boots, and I plan on wearing it that way as well, or over jeans. Sweater dresses are hard for me to find, so when I find a good one it's a no brainer for me. A few ideas for color... Try adding dark blue jeans and a statement pearl piece, per Angie's "black and ink blue" blog post recently. I plan on trying to soften my blacks with ink blues this fall, and of course adding a cream accessory.
Try purples, greys, or french blues also. Black is so versatile and you can wear almost every color or texture with it. For a vintage look, try a long strand of pearls doubled up, or a vintage necklace.