01 - Preheat oven to 325°F. Grease a 9-inch springform pan and line the bottom with parchment paper.
02 - Combine graham cracker crumbs, granulated sugar, pinch of salt, and melted unsalted butter in a bowl. Press the mixture evenly into the bottom of the prepared pan. Bake for 10 minutes, then allow to cool completely.
03 - In a large mixing bowl, beat softened cream cheese until completely smooth using an electric mixer. Add granulated sugar and vanilla extract; mix until just combined.
04 - Add eggs one at a time, mixing just until incorporated after each addition. Blend in sour cream and all-purpose flour until the batter is smooth.
05 - Divide the cheesecake batter evenly among three separate bowls. Leave one portion plain. Color one bowl with red gel food coloring and the other with blue gel food coloring until the desired intensity is reached.
06 - Drop alternating spoonfuls of each colored batter onto the cooled crust, creating a patchwork pattern. Use a skewer or knife to gently swirl the batters for a marbled design, taking care not to overmix.
07 - Bake in the center of the oven for 50 to 60 minutes, or until the center is just set but still slightly jiggly.
08 - Turn off the oven, crack the oven door open, and let the cheesecake cool inside for 1 hour.
09 - Remove the cheesecake from the oven and chill in the refrigerator for at least 3 hours before slicing and serving.