To prepare Graham Cracker Piecrust: In a medium bowl, stir together crushed graham crackers, margarine and sugar. Pat the crumb mixture evenly onto the bottom and up the side of a 9-inch pie plate. Set aside.
To prepare No-Bake Lime Pie: Soften gelatin: In a small saucepan, stir together gelatin and ½ cup of the milk; let stand about 5 minutes or until gelatin is softened (the mixture will be thick). Cook and stir over low heat until the gelatin is dissolved.
For filling, in a large bowl, beat cream cheese with an electric mixer on low speed until smooth. Beat in lime juice, sugar and food coloring. (The mixture will thicken slightly when lime juice is added.) Gradually beat in the remaining 1- ¼ cups milk and gelatin mixture. Cover and chill about 30 minutes or until mixture mounds when lifted with a spoon, stirring occasionally.
Pour the chilled filling into Graham Cracker Piecrust. Cover pie loosely; chill for 4 to 24 hours. Before serving, top with dessert topping and lime peel, if desired.
Tip: If using a sugar substitute, choose Equal® Spoonful or packets. Follow package directions to use product amounts equivalent to 1 teaspoon and 2 tablespoons sugar.