Light roasts are light brown in color, with a light body and no oil on the surface of the beans. Light roasts have a toasted grain taste and pronounced acidity. The origin flavors of the bean are retained to a greater extent than in darker roasted coffees. Light roasts also retain most of the caffeine from the coffee bean.
Some are better able to taste the difference between a Colombian (full body, some floral notes) and say a Kenyan (bright wine acidity) and a Sumatran (earthy and mossy). Not all coffees are great light roasted, some have undesirable tastes like peanuty, vegetabley, cocoay. Often coffees that are light roasted don’t taste balanced (meaning equal amounts of body, acidity and fruitiness. The problem is that some customers just don't like light roasted coffee becasue it can taste extreme.
Some common roast names within the Light Roast category are Light City, Half City, Cinnamon Roast (roasted to just before first crack), and New England Roast (a popular roast in the northeastern United States, roasted to first crack).