Prepare the popcorn by popping a batch using your preferred method and spread it evenly on a large baking sheet lined with parchment paper or silicone mat. Let it cool slightly to prevent melting when coating.
In a double boiler or microwave-safe bowl, melt the white sugar with a few tablespoons of water over low heat, stirring constantly until the mixture becomes smooth and slightly thickened, about 3-5 minutes. Alternatively, melt candy melts separately in microwave-safe bowls, stirring every 30 seconds until fully melted and smooth.
Divide the melted candy melts evenly into two bowls. Add the red candy melts to one bowl and the blue candy melts to the other. Stir each until fully combined and smooth, ensuring the colors are vibrant.
Using a spoon or spatula, drizzle or coat the popcorn with the melted red candy over half of the popcorn surface, then do the same with the blue candy on the other half. Use a spatula to gently toss and distribute the coatings evenly across the popcorn. Allow the coatings to set and harden at room temperature for about 10 minutes.
Once the coatings are hardened, sprinkle the red candies over the red-coated areas and the blue candies over the blue-coated areas, pressing lightly to embed them into the surface. Let the mixture sit for an additional 10-15 minutes to ensure everything is set and crisp.
Break apart any clusters as needed and transfer the finished patriotic popcorn mix to a serving bowl or container. Serve immediately or store in an airtight container for up to 2 days for optimal freshness.
