Crust:

1 (5 1/3 oz.) pkg. graham crackers, crushed (about 1 1/2 cup)
1/2 c. macadamia nuts (finely chopped)
1/4 c. sugar
6 tbsp. butter (melted)

Tart:

1/2 c. fresh lime juice (about 6 large limes)
1 c. sugar
6 tbsp. butter
1 drop green liquid food coloring (optional)
1 drop yellow liquid food coloring (optional)

Garnish:

Toasted macadamia nuts
Lime slices
Whipped cream

Crust: Stir together the first four ingredients, firmly press crumb mixture evenly on bottom and up the sides of a 10 inch tart pan.

Bake crust at 350°F for 7 to 9 minutes, cool on wire rack.

Tart: Whisk together eggs, grated lime rind and fresh lime juice in a non-aluminum saucepan over low heat. Add 1 cup sugar, 6 tablespoon melted butter and if desired food coloring. Cook for 8 minutes or so whisking constantly until lime mixture is thickened and bubbly. Let cook 15 to 20 minutes. Pour filling into prepared crust. Cover and chill for 4 hours or until set. Remove sides of tart pan and garnish if desired.