Brian – Some coffees, when properly roasted, will have a mild flavor; the Mexican Chiapas comes to mind, as does a Guatelama Antigua Serano.
I think what you might mean, though, is a light roast. Coffee beans, before they are roasted, are green and very hard; if you don’t roast them enough, they won’t lose enough density/moisture to grind well or taste good, at all. Also, under-roasted coffee tastes grassy.
I asked my husband (the roaster; our company is Ristretto Roasters, here in Portland, OR) about light roasts, and he said, “There’s all sorts of terminology — ‘cinnamon’ and ‘city-roast’ and ‘full city,’ and none of it’s very useful.” I think, also, the balance has recently been so skewed dark, that what is sometimes considered a “light roast” is what we call a medium.
