Puree the raspberries in a small food process or blender until smooth. Set aside.
Puree the blueberries. If your blueberries turn out purple (like mine did) go ahead and add some blue food coloring to your puree. Set aside.
Add water to the yogurt and mix it together in the blender. Set aside.
I'd suggest adding a touch of yogurt to brighten up the blue of the blueberry. (You can see from my pictures mine turned out dark and purple) Keep all three cups chilling in the refrigerator when you are not using them.
To layer your pops, start by pouring a little of the blueberry in the bottom of each mold.
Put the mold in the freezer and freeze till firm, at least an hour, or more.
Layer a little bit of yogurt into each mold for the next stripe. You will be able to see through the side of the mold to check your progress. At this point, insert the popsicle sticks. Make sure to get the stick a little bit into the frozen layer so they will stand straight. Put back into the freezer until solid.
Next comes your raspberry stripe- repeat until the molds are filled. Make sure to freeze each stripe until solid before adding the next. The next time I make these I'll make the stripes thinner. Don't worry if the stripes are uneven, but do try to clean up any dribbles on the edge of the mold as you go.
Once filled and completely frozen solid, you can un-mold your pops. Fill the sink with hot water and immerse the mold just up to the lip, being careful not to let any water splash onto the top. Hold it for 30 seconds, remove, and try to pull the pops out. If they don't slide out, immerse again for just a few seconds.
Serve immediately and enjoy :)