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, salt, and melted butter in a mixing bowl. Press mixture firmly into the bottom of the prepared pan to form an even layer. Bake for 10 minutes, then set aside to cool.
03 - In a large bowl, beat the softened cream cheese until smooth using an electric mixer. Add granulated sugar and vanilla extract, mixing until just combined.
04 - Add eggs one at a time, mixing gently after each addition. Blend in sour cream and all-purpose flour until a smooth, homogenous batter forms.
05 - Evenly divide the batter among three bowls. Leave one uncolored. Add red gel coloring to one bowl, blue gel coloring to the other, and mix each until fully tinted to the desired intensity.
06 - Alternate dropping spoonfuls of each colored batter onto the cooled crust to form a patchwork design. Gently swirl batters together with a skewer or knife for a marbled appearance, ensuring swirls remain distinct.
07 - Bake in the preheated oven for 50–60 minutes, or until the center is almost set with a slight jiggle. Turn off the oven, crack the door, and allow the cheesecake to cool inside for 1 hour.
08 - Remove from the oven and refrigerate at least 3 hours to fully chill prior to slicing and serving.