Preheat oven to 200°. Line a rimmed baking sheet with parchment paper.
In a medium bowl, stir together sugar and lemon zest. Stir in food coloring (if using), one drop at a time, until desired color is reached. Spread sugar mixture onto prepared pan.
Bake for 10 minutes, stirring halfway through baking. Let cool completely. Break up clumps with a fork. If you prefer a fine sugar, pulse mixture a few times in the work bowl of a food processor. Store in an airtight container for up to 1 month.
Recipe by Paula Deen Magazine at https://pauladeenmagazine.com/lemon-sugar/