Preheat oven to 375℉. Line a baking sheet with a silicone baking mat or parchment paper.
Combine 1 cup of sugar and ¾ cup of butter in a large bowl. Beat at medium speed, scraping the bowl often, until creamy.
Add egg and continue beating until combined. Reduce speed to low and add flour, baking powder, and salt. Beat until combined.
Place colored sugar in a small bowl. Shape dough into 1-inch balls using a cookie scoop. Dip the top of each dough ball in sugar.
Place 2 inches apart onto the prepared cookie sheets.
Bake for 10 to 14 minutes or until the edges are very lightly browned. Remove from cookie sheets to a cooling rack to cool completely.
Store in an airtight container.