Line an 8x8 pan with parchment paper, making sure that the parchment paper extends past the pan so that you can lift the fudge out of the pan after it sets.
In a large microwave-safe bowl, combine 1 ½ cups of white chocolate chips, ½ of the sweetened condensed milk, and half of the salt. Stir to combine. Microwave for 30 second increments, making sure to stir in between, until mostly melted. Then, stir until fully melted and smooth.
Stir in the vanilla extract. Add 2-4 drops of food coloring (until you reach your desired coloring), and mix until thoroughly incorporated.
Spread the fudge mixture into the bottom of the pan in an even layer, and allow it to sit for about 30 minutes to set.
Once the first layer is set, repeat the process again, but do not add food coloring to this layer. Spread the fudge over the first layer.
Place the Valentine’s day sprinkles on top of the fudge, use your hands to slightly press the sprinkles in to make sure they stay in place after they set. Allow it to set for 2 hours.
When firm, pull the edges of the parchment paper out of the pan, and pull the paper away from the fudge. Set the fudge on a cutting board and but into squares.
Store in an air-tight container at room temperature.