In a glass, pour in the pineapple juice, orange juice, 1 ounce dark rum, and 1 ounce coconut rum. Gently stir. Then slowly pour in a splash of grenadine. The grenadine will sink to the bottom giving you that gorgeous coloring. Then, add 1/2 ounce of the dark rum to the top. Garnish with a slice of lime and float away into a tropical paradise. A cute straw helps, too.
Although the drink looks gorgeous, I like to give it a little stir to get everything all mixed up before sipping the day way.