Line a large baking sheet with a Silpat mat or parchment paper, ensuring it lies completely flat without wrinkles.

Set up double boiler with two pots of different sizes with 1 inch water in each. Bring to gentle simmer (small bubbles, not rolling boil). Place candy melts in separate heat-proof bowls over smaller pot, stirring frequently until smooth, 3-4 minutes per color. If candy melts seize, remove from heat and stir in 1 teaspoon coconut oil.

Melt white chocolate in larger bowl over bigger pot, stirring constantly for 5-7 minutes until silky smooth and warm to touch (100-105°F). Chocolate should pour in smooth ribbon when lifted with spoon.

Quickly spread melted white chocolate onto prepared baking sheet using offset spatula, creating even 1/4-inch thick layer from center outward.

Drop small spoonfuls (about 1 teaspoon each) of colored candy melts randomly across white chocolate surface, then use toothpicks to create gentle swirl patterns without over-mixing.

Immediately sprinkle Christmas candies and sprinkles over surface while warm. Press gently to ensure they stick.

Refrigerate for 30 minutes or let set at room temperature for 2 hours until completely firm. Use sharp knife to cut into approximately 16 pieces.