You will need some vodka and orange juice. Take your shaker and fill with ice. Add the orange juice to the ice. Set aside to chill. Next pour off the right amount of vodka you will need. Mix a teaspoon each of green and red food coloring. Add it to the vodka and stir. This should make your vodka appear black. Pour some sugar on a plate and take your martini glass, place it upside down in the sugar, and spin it so the rim of the glass is covered. Put some ice in the glass and fill half the glass with chilled orange juice. Then pour the vodka over a spoon right above the orange juice. This should allow the black vodka to swim on top of the orange juice.