01 - Preheat oven to 325°F. Lightly 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 bowl. Press mixture firmly into the bottom of the prepared pan. Bake for 10 minutes, then allow to cool.
03 - Beat cream cheese in a large mixing bowl until completely smooth. Add sugar and vanilla extract, mixing well to fully incorporate.
04 - Add eggs one at a time, blending just until incorporated after each addition. Stir in sour cream and all-purpose flour until the batter is smooth.
05 - Separate the batter evenly into three bowls. Leave one bowl uncolored. Blend red gel food coloring into one bowl and blue gel food coloring into another until desired hues are achieved.
06 - Alternate spoonfuls of plain, red, and blue batters onto the cooled crust to form a patchwork pattern. Gently swirl with a skewer or knife for a marbled effect, taking care not to overmix.
07 - Bake for 50 to 60 minutes, or until the center is just set but retains a slight jiggle. Turn off the oven, crack the door, and allow the cheesecake to cool inside for 1 hour.
08 - Remove from oven and refrigerate for at least 3 hours, ensuring full set before slicing.