Black is great too, but I kind of find the dark brown ones a little more unexpected. I can also see the brown working really well with the colours in your wardrobe, Jean, and they are great for bookending your hair (if that's something you'd like to do). I also like it that the heel on this pair is also brown and not black, which happens a lot.
Does 6PM offer free returns? Perhaps you could order the brown then and play around with them in your closet to see how they work with some outfits you'd like to use them for?