Pour the yogurt into a bowl - if you are using different flavored yogurts then put them each into their own bowls.
Heat the water, sugar, blueberries, and lemon zest in a saucepan over medium heat. Stir the berries often, mashing them, for 5-7 minutes. Remove from the heat and let it cool for a few minutes before pouring through a strainer. Let the blueberry sauce cool completely.
Pour a bit of the blueberry sauce, to taste, into the bowl(s) of yogurt(s). Gently stir just a little bit to swirl blueberry sauce with yogurt - don't mix thoroughly. Pour into each popsicle mold.