Prepare the Base – In a large mixing bowl, combine whipped topping, pistachio pudding mix, and green food coloring (if using). Stir until well blended.
Fold in Ingredients – Gently fold in the miniature marshmallows and undrained pineapple tidbits, ensuring an even distribution.
Chill to Set – Cover the bowl and refrigerate for at least 2 hours to enhance the flavors and set the texture.
Garnish & Serve – Before serving, top with extra whipped topping (if desired) and sprinkle with chopped pistachios or walnuts for added crunch.