In a large bowl, mix together flour, salt, baking powder and sugar; set aside. Preheat waffle iron to desired temperature.
In a separate bowl, beat the eggs. Stir in the milk, butter and vanilla. Pour the milk mixture into the flour mixture; beat until blended.
Ladle the batter into a preheated waffle iron. Cook the waffles until golden and crisp. Serve immediately.
How do you make the rainbow? We divided the batter into 5 bowls and used food coloring to color each a different color. We used red green blue yellow and purple. These were then transferred to squeeze bottles.
Now the fun part! using the squeeze bottles, in a circular motion, layer the colors in the waffle iron and close the lid to wait for the color magic!
When the waffles are cooked, you can see your creation!