Place the crust ingredients, except for the butter, in a food processor and combine until thoroughly combined. While the processor is still running, stream in the melted butter until mixture is wet. Press into greased individual tart pans (mine are 4 inch) and bake for about 8 minutes, or until cooked through.
In a medium saucepan set over medium heat, combine the sugar with the cornstarch and add in the juice. Cook, stirring, until thickened and bubbly. Whisk in a few tablespoons of the hot mixture into the egg yolks to temper the eggs. Return the egg mixture to the saucepan and cook, stirring constantly, until the mixture thickens, about 2-3 minutes. Remove from heat and add in the butter pieces. Whisk until melted. Stir in food coloring.
Pour the mixture into the cooled crust and smooth the top. Chill in the fridge for at least 4 hours before serving.