01 - Preheat oven to 325°F (163°C). Grease a 9-inch springform pan and line the base with parchment paper.
02 - Combine graham cracker crumbs, granulated sugar, salt, and melted butter in a mixing bowl. Press the mixture firmly into the bottom of the prepared pan. Bake for 10 minutes, then allow crust to cool.
03 - Using an electric mixer, beat softened cream cheese until smooth. Blend in granulated sugar and vanilla extract until incorporated.
04 - Add eggs one at a time, mixing gently after each addition. Fold in sour cream and flour until the batter is creamy and homogenous.
05 - Portion batter evenly into three bowls. Leave one portion plain, tint one with red gel food coloring, and the last with blue gel food coloring, mixing each until the desired hue is obtained.
06 - Alternate spoonfuls of each colored batter over the cooled crust to create a patchwork. Swirl gently with a skewer or knife to achieve a marbled pattern, being careful not to overmix.
07 - Bake in the center of the oven for 50 to 60 minutes, until the center is nearly set but still slightly wobbly. Turn off the oven, crack the door, and let cheesecake cool inside for 1 hour.
08 - Remove cheesecake from oven and refrigerate for at least 3 hours, ensuring it is thoroughly chilled before slicing and serving.