01 - Divide the shredded cheeses evenly into three separate mixing bowls. In the first bowl, incorporate the spirulina powder until the cheese is uniformly colored blue/green. In the second bowl, mix in the beet powder for a pink/red hue. In the third bowl, blend in the turmeric powder for a vibrant yellow. Stir each until the color is evenly distributed throughout the cheese.
02 - Optionally, gently mix a small amount of cream cheese into each bowl of colored cheese. This will aid in binding the cheese together and ensure a smoother, creamier melt.
03 - Lay out the four slices of bread. Lightly spread softened butter on one side of each slice. On the unbuttered side of two bread slices, artfully arrange the colored cheeses in random patterns or stripes to achieve a 'chaos' effect. If using, scatter the chopped baby spinach over the cheese layers.
04 - Place the remaining two bread slices on top of the cheese-covered slices, ensuring the buttered side of the top bread slices faces outward. Heat a nonstick skillet or griddle over medium heat. Carefully place the assembled sandwiches into the heated skillet. Cook for approximately 3 to 4 minutes per side, applying gentle pressure with a spatula, until the bread is golden brown and the cheese is fully melted and gooey.
05 - Remove the grilled cheese sandwiches from the skillet. Allow them to cool slightly before cutting them in half diagonally or horizontally to reveal the colorful interior. Serve immediately while hot.