Butter one side of each slice of bread and set aside.
Divide the shredded cheese into four bowls and add a couple drops of food coloring: yellow to one, red to one, blue to another, and red and blue to make purple in the 4th. Stir the food dye into the cheese.
Cut the slices of provolone in half and place one on each slice of bread - on the unbuttered side. Sprinkle 1-2 Tablespoons of the colored cheese in "lines" or strips on top of 4 of those slices, overtop of the provolone, in the order of ROYGBIV (mix the red and yellow to make orange, yellow and blue to make green).
Sandwich a slice of bread with provolone over the shredded cheese and place in a frying pan over medium heat.
Cook until golden brown, about 2 minutes, and then flip.
Remove to a plate and serve.
Optional: top with colorful sprinkles to make Unicorn Grilled Cheese!
Notes
You can alternatively add one single color for a birthday, team colors for a game day, or a mix of princess colors – whatever suits the occasion!
Top with colorful sprinkles to make Unicorn Grilled Cheese!
Don't cut completely through the cheese so you can encourage the kids to pull their sandwiches, revealing the fun colors inside.