Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large bowl, cream the butter and sugar until light and fluffy using an electric mixer.
Beat in the eggs and vanilla extract until well combined.
In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients and mix until just combined.
Divide the dough into four equal portions and place each portion into a separate bowl.
Add one package of Jello to each bowl and mix until the dough is evenly colored.
Roll each portion of dough into 1-inch balls.
Roll each ball in additional granulated sugar to coat.
Place the balls onto the prepared baking sheet, leaving about 2 inches between each cookie.
Bake for 10-12 minutes, until the edges are just starting to turn golden brown.
Remove from the oven and allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.