Make a simple syrup by combining water and sugar in a small pot. Bring to a boil and simmer for about 4-5 minutes on medium heat.
Set syrup aside to cool.
Puree each fruit separately in a blender until smooth.
Divide the cooled simple syrup evenly among the three fruit purees and mix well.
Fill four small popsicle molds halfway with the kiwi puree and place in the freezer for at least 1 hour.
Add a layer of mango puree on top of the kiwi layer and freeze for another 20 minutes.
Insert popsicle sticks and freeze until firm, about 2-3 hours.
Top with raspberry puree and freeze overnight, or until completely solid.
Notes
For best results, ensure each layer is partially frozen before adding the next to prevent colors from blending too much. If you prefer a less sweet pop, you can reduce or omit the sugar in the syrup.