Preheat oven to 350°F. Line a baking sheet with parchment paper and set aside.

Cream the butter and granulated sugar in a mixing bowl until light and fluffy. Mix in the egg and vanilla.

In a separate medium bowl, whisk together the flour, baking powder, baking soda, and cream of tartar. 

Add the flour mixture to the butter mixture and mix until a soft dough forms.

Divide the dough into four equal portions, placing each portion of dough in a separate small bowl.

Add 2 tablespoons of Jello to each bowl, using different flavors for each bowl. Add the coordinating food coloring to the same bowl. Using clean hands, knead the Jello and food coloring into the cookie dough until it is thoroughly combined.

Scoop balls of dough into 1-inch balls. Using clean hands, roll the dough into balls, then lightly roll the balls into the remaining coordinating color of jello powder. 

Place the cookie dough balls onto the baking sheet, 2 inches apart, then flatten each ball slightly with the bottom of a glass.

Bake for 8-10 minutes or until the edges just begin to brown. 

Remove the cookies from the oven and allow them to rest on the baking sheet for 3-5 minutes before transferring them to a cooling rack to cool completely.