Put the lime juice, condensed milk, strawberries, tequila, and triple sec in a blender and puree until smooth.
Place cups on a baking sheet or other dish that will fit in your freezer. Pour mixture evenly among the cups. Insert a popsicle stick in a lime/strawberry slice and place in the cups on top of the mixture with a few inches of the stick in the liquid.
Freeze until solid. Store in a zip to lock bag if desired to store for longer than a day or two.
To serve: remove from cups and sprinkle with colored sugar.