Few characteristic of each different roasting level reference for you to better know your preferences.
Light brown in colour, with a light body absent of oil on the surface of the beans. Light roast have a toasted grain taste and high in the level of acidity. Light roast coffee beans retain most of the caffeine from the coffee bean.
Medium brown in colour with more body than light roast. There is also an absence of oil on the surfaces. However, medium roast lac of the grainy taste of the light roasts. Hence, providing more balanced flavor, aroma, and acidity. Caffeine decreases in medium roast beans.
Dark roast have a richer, darker brown colour showing on the surface. There is an presence of oil on the surface of the beans. A dark roast has a heavy body in comparison to light and medium roast. The coffee will generally have a bitter and smoky or even burnt taste.