1. Preheat your oven to 375°F (190°C).

2. In a large bowl, combine the flour, 1/2 cup of the butter, and 1/4 cup of the sugar. Mix until the mixture resembles coarse crumbs.

3. Press the dough into a 9-inch pie dish, forming a crust on the bottom and up the sides.

4. In a separate bowl, beat the remaining 1/2 cup of butter and 3/4 cup of sugar until light and fluffy.

5. Add the eggs, one at a time, beating well after each addition. Stir in the vanilla and salt.

6. Divide the filling mixture into two equal parts. Add a few drops of green food coloring to one half and mix well, creating a vibrant green filling.

7. Spoon the green filling and the plain filling into the prepared pie crust, alternating spoonfuls to create a swirled pattern.

8. Bake for 35-40 minutes, or until the filling is set and the crust is golden brown.

9. Allow the pie to cool completely before slicing and serving.