Preheat oven to 350 degrees.
In a large mixing bowl, mix together melted butter and 3/4 cup sugar.
Mix in egg yolks, vanilla extract, and food coloring to achieve your desired Grinch green.
Gently stir in flour, baking soda, and salt until just combined.
Scoop out about 1.5 tablespoon portions of dough and roll into balls.
Roll cookie dough balls in remaining 1/4 cup sugar, then place on baking sheet lined with parchment paper.
Bake for 9-10 minutes until the middle of the cookies look crackly and done.
Remove from oven and while cookies are still warm, press in your heart sprinkles.
Allow to cool and enjoy!