Pop the popcorn using an air popper or stovetop method, then place it in a large mixing bowl. Make sure to remove any unpopped kernels.
In a microwave-safe bowl, melt the white chocolate chips in 30-second intervals, stirring in between until smooth. Drizzle the melted white chocolate over the popcorn and gently toss to coat.
Spread the popcorn evenly onto a large baking sheet lined with parchment paper.
In separate bowls, melt the blue and red candy melts in the microwave, also in 30-second intervals, stirring until smooth.
Drizzle the melted blue candy melts over half of the popcorn and the red candy melts over the other half. Use a spatula to gently mix the popcorn to create a marbled effect.
Sprinkle the sea salt and the red, white, and blue sprinkles over the popcorn while the candy melts are still wet.
Allow the popcorn to cool completely at room temperature, about 30 minutes, until the candy coating hardens.
Once set, break the popcorn into clusters and serve in festive bowls or bags.