I have dark brown hair and I've been using Espresso forever! I usually comb my brows with a spooly to lighten it up a little and to make it look more natural afterwards.
let me be offtopic a bit...
My opinion that the best e/s for brows is Clarins shade-09 Chestnut freeze. it's matte brown/greyish. I don't like redish brown cos it looks funny applied on my brows.
just love it, it looks so natural...