There are a variety of ways to make a drink black without using activated charcoal. Use a mix of food coloring (start with blue, add a little red and a dash of green). Grab a Halloween mix of edible glitter and use the black option for a shiny black look. Or use something like black vodka to give the drink its color. You can also use natural items like blackberries, etc. but you can't always get a true black color that way.