Cream Butter and Sugars
In a large bowl, beat softened butter, granulated sugar, and brown sugar on medium speed for 3–4 minutes until light and fluffy.

Add Wet Ingredients
Beat in eggs one at a time, mixing well after each addition. Stir in vanilla extract until smooth.

Mix Dry Ingredients
In a separate bowl, whisk flour, baking soda, and salt. Gradually mix into wet ingredients on low speed until just combined. Do not overmix.

Fold in Chocolate Chips
Gently stir in chocolate chips with a spatula until evenly distributed.

Divide and Color Dough
Divide dough into 4 equal portions (about 1⅓ cups each). Place each in a separate bowl. Add a small amount of gel food coloring (using a toothpick) and gently knead until evenly tinted. Add more color gradually to achieve soft pastel tones.

Chill (Optional)
Refrigerate dough for 15–20 minutes if it feels too soft. This helps prevent colors from blending too much.

Create Marbled Dough Balls
Take 1 tablespoon of each colored dough and loosely press together. Twist gently once or twice to create a swirl effect, then roll lightly into a ball. Repeat to form about 24–28 cookies.

Preheat Oven
Preheat oven to 350°F (175°C). Line baking sheets with parchment paper or silicone baking mats.

Bake
Place dough balls 2 inches apart on baking sheets. Bake one sheet at a time for 10–12 minutes. Edges should be lightly golden while centers look slightly soft.

Cool
Let cookies rest on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.