Begin by placing your crispy rice cereal squares into a large mixing bowl, ensuring there's enough space to stir gently without spilling.

In a microwave-safe bowl, combine the white chocolate chips and butter. Heat this mixture in 30-second bursts at medium power, stirring vigorously until fully melted and smooth.

Once melted, add the lemon zest, fresh lemon juice, vanilla extract, and food coloring (if using) to the bowl. Stir everything together until cohesive.

Gently pour the melted lemony mixture over the cereal in the mixing bowl. Using a spatula, carefully fold the cereal with the chocolate mixture.

Grab a large resealable plastic bag and pour in the powdered sugar. Carefully add the coated cereal in batches, sealing the bag tightly. Shake gently until covered.

Spread the coated cereal out on wax paper or a parchment-lined baking sheet. Let it cool for about 30 minutes to firm up.