What is the process behind the color changing effect in a color changing popsicle?

The color changing effect in a color changing popsicle is typically achieved through the use of pH-sensitive compounds called anthocyanins. These compounds change color in response to changes in acidity levels. When the popsicle is exposed to acidic conditions, such as when it is licked or melted in the mouth, the anthocyanins react and change color, creating the color changing effect.