In 9-inch glass pie plate, melt margarine in microwave oven at HIGH (100% power) 1 to 1 1/2 minutes.
Add pretzels and sugar; mix well.
Press mixture firmly in bottom and up side of pie plate.
Refrigerate crust while preparing filling.
In 4-cup glass measure combine sugar, lime peel, lime juice and salt.
Cook in microwave oven at HIGH (100% power) 1 to 1 1/2 minutes or until sugar dissolves, stirring once.
Slowly add eggs to lime juice mixture, whisking constantly.
Cook at HIGH 30 seconds; stir mixture.
Continue cooking at HIGH until mixture thickens, stirring every 15 seconds.
In 1-cup glass measure sprinkle gelatin over combined tequila and Triple Sec.
Let stand 1 minute to soften.
Cook gelatin mixture at HIGH 45 seconds or until gelatin dissolves.
Add gelatin mixture and food coloring to lime mixture.
Refrigerate 1 hour or until mixture is cool and slightly thickened.
Fold in whipped topping and pour into prepared pretzel crust.
Chill several hours or until set.