Divide the Greek yogurt into three equal portions in separate bowls. Leave one portion plain for the white layer.
Stir the blended pineapple into the second portion of yogurt until the color turns even yellow.
Stir the blended mango into the third portion of yogurt until the color turns even orange.
Spoon the yellow pineapple yogurt into the bottom of four clear glasses, using about two tablespoons per glass.
Add the orange mango yogurt on top of the yellow layer in each glass, again using about two tablespoons per glass.
Finish with the plain white yogurt layer on top.
Place a few pieces of candy corn on the surface of each parfait just before serving.