Espresso doesn't have to be dark! True, it generally is, but the reason many equate espresso with dark, oily beans is because that is what Starbucks, Peets, etc. produce. Why does Starbucks do this? Cuts through milk better than a lighter roast, and milk-based drinks (e.g. lattes, cappucinos) are Starbucks' sweet spot.

Try the Code Brown mentioned above or Taste of Milan (even lighter). No milk needed. In fact, I like shots of those straight.

Bottom line: espresso isn't necessarily a dark roast.