Preheat your oven to 350°F (175°C) and grease a loaf pan.
In a medium bowl, whisk together the all-purpose flour, baking soda, and salt.
In a large bowl, cream the unsalted butter and granulated sugar together until light and fluffy. Add in the eggs one at a time, mixing well after each addition.
Gently incorporate the mashed ripe bananas and vanilla extract into the butter-sugar mixture until smooth.
Gradually fold in the dry ingredients until just combined.
Divide the batter into separate bowls and add gel food coloring, mixing until the desired shades are achieved.
Alternately spoon the colored batters into the prepared loaf pan, adding sprinkles between layers.
Gently swirl the colors together using a knife, but keep colors distinct.
Bake for 50-60 minutes, checking with a toothpick for doneness.
Let the bread cool in the pan for about 10 minutes before transferring it to a wire rack.
Mix powdered sugar and milk for the glaze. Once the bread is cool, drizzle the glaze over and top with extra sprinkles.