Soften the gelatin in the cold water.
Combine the sugar, salt and hot water in a saucepan; heat to boiling, stirring constantly.
Stir in the softened gelatin; turn the heat down and simmer, without stirring, for 20 minutes.
Remove from the heat and stir in the grated rind, orange and lemon juice, and a little red food coloring to tint the mixture a bright red {1/4 teaspoon is about right).
Let stand 3 minutes.
Strain the mixture into a 8 x 4-inch loaf pan which has been rinsed with cold water.
Let stand without disturbing until slightly jellied (to prevent filming the sides of the pan); then refrigerate overnight.
Loosen around the sides of the pan with a wet spatula.
Slip the spatula down one end and underneath the jellied mixture, then pull it out of the pan with your hands.
Cut into 1-inch squares.
Roll in confectioners' sugar to coat.Store in one layer in a tightly covered container at room temperature.
The candies will stay moist for about 2 weeks.