Preheat the oven to 350.
Make the crust: In a bowl mix together the cookie crumbs, melted butter, powdered sugar and fine sea salt. Take 1/2 of the mix and press it into the bottom of a 8-9 inch tart pan with a removable bottom with your fingers. Press the rest around the sides. Use the bottom of a rounded cup or measuring cup to pack it in and smooth the crumbs.
Bake the crust for about 7 minutes. Allow to cool to room temperature then set in the freezer.
Beat the cream cheese with the sugar, lemon zest and juice, vanilla and salt until just smooth (don’t over-beat). Stir in the sour cream.
In a separate bowl whip the heavy cream to stiff peaks (when you lift up your beaters the cream will hold shape).
Fold the heavy cream into the cream cheese mix.
Into three bowls add 1/2-2/3 cup of the mixture, leaving at least a cup of mix aside.
Add food coloring to each bowl and stir. If you find it gets too runny, add 1-2 tablespoons powdered sugar.
Alternate adding the colors in large dollops into the frozen crust. Once you’ve used up all the filling, use a butter knife to swirl the mix making 2-4 large 8 shapes in the pan.
Transfer to fridge to set overnight.