Pop the popcorn using an air popper or on the stovetop. Place the popped popcorn in a large mixing bowl, removing 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.
Melt the red candy melts in a separate microwave-safe bowl using the same method as the white chocolate. Once melted, drizzle over the popcorn and toss gently to combine.
Repeat the melting process for the blue candy melts, drizzling them over the popcorn and tossing to coat.
Add the mini marshmallows and sprinkles to the popcorn mixture, and gently fold them in until evenly distributed.
Spread the popcorn mixture onto a large baking sheet lined with parchment paper. Sprinkle with sea salt.
Allow the popcorn to cool completely before breaking it into clusters for serving.