In a saucepan, bring the sugar and 125 ml (approximately 1/2 cup) of water to a boil, stirring until the sugar has dissolved. Soak the gelatin in lukewarm water. In a bowl, stir the cornstarch into a little cold water until thoroughly moistened. Stir the cornstarch mixture into the sugar mixture and cook until thickened, about 1 minute. Remove from the heat and divide the mixture in half.
For red Turkish delight: Stir the rose water and cherry juice into one-half of the sugar mixture. For the yellow Turkish delight: Stir the orange flower water and orange juice into the other half. Remove the syrup from the heat. Squeeze the gelatin, divide in half and stir one-half into each of the colored mixtures. Pour each mixture onto a sheet of parchment paper and flatten each into a square about 15 x 15 cm (approximately 6 x 6-inch) Cool completely. Cut the jelly into rectangular pieces and roll in powdered sugar.