Fill the cocktail shaker with a handful of ice cubes to chill it down.
Add the tequila, fresh lime juice, and triple sec into the shaker using a measuring jigger for accuracy.
Drop in two small droplets of black food coloring—this is enough to give the drink its dark hue without overpowering the flavor.
Secure the lid tightly on the shaker and shake vigorously for about 15 seconds until the mixture is well chilled, the color is uniform, and you hear a satisfying rattle.
Strain the mixture into a chilled glass to remove ice shards and achieve a smooth, velvety surface.
Garnish with a lime or lemon wedge on the rim or float a twist of citrus peel for an extra touch of color and aroma.
Serve immediately, showcasing its deep black color and inviting aroma, ready to impress for Halloween or a spooky night.
