Beat cream in a chilled glass or metal bowl with an electric mixer until soft peaks form.
Mix Neufchatel cheese and green food coloring in a mixing bowl with an electric mixer on low until smooth and even in color. Add gelatin mixture and continue mixing to incorporate. Reserve a pinch of lime zest for garnishing the fishing pie; beat lime zest and lime juice into the cheese mixture. Fold the whipped cream into the cheese mixture using a spatula; spread into the prepared pie crust. Garnish with the reserved lime zest.
Cover pie loosely with plastic wrap and refrigerate until set, about 4 hours.