The difference between light and dark rum includes the appearance, caramel content and the type of container in which each variety ferments. Light rum, which is colorless and contains no caramel, ferments in steel casks and undergoes stringent filtering before bottling. Dark rum, which ferments in charred oak barrels, is a deep brown shade. The color comes from caramel and deepens as the rum ferments.
A third category of rum is called amber rum, and like dark rum, it ferments in oak barrels. Unlike the barrels used for dark rum, however, these are not charred. Amber rums have a richer, more complex flavor than white rum but are not as rich as true dark rum.
Another type of rum, spiced rum, contains a heady plethora of spices and other flavorings. Its color and flavor profile changes based on the ingredients used by each distillery. Like flavored vodka, spiced rum is often made at home. According to mixologist and About.com Guide Colleen Graham, common flavors found in commercial and homemade spiced rums include ginger, black pepper, clove, cinnamon, vanilla and allspice. Spiced rum intended for use in tropical drinks often includes mango, pineapple or papaya juice.
All types of rum also have variations called rum creams. These high-fat liqueurs are popular in cocktails such as the White Russian and Black Russian. Rum cream may be purchased or blended at home.