"Dark beer" refers to a type of alcoholic beverage that has a rich, deep color. It is generally fuller in flavor, often featuring roasted or toasted malt characteristics. Full definition
Serve this dreamy, cheesy, Irish - inspired bread pudding with dark beers as a hearty first course, or pair it with a salad and call it dinner. (epicurious.com)
Lastly, you'll also need a half - cup of dark beer. (cabotcheese.coop)
Generally, it also takes a little longer to drink a good dark beer compared to a watery light beer too. (truthaboutabs.com)