In a medium bowl, combine graham cracker crumbs, melted butter, and white sugar. Mix until well-coated and resembles wet sand. Press firmly into the bottom of mini dessert glasses.

In a large bowl, beat the cream cheese and yogurt with an electric mixer until smooth, about 2-3 minutes. In another bowl, whisk together the condensed milk and lime juice, then gradually mix into the cream cheese mixture.

If coloring, divide the filling and add food coloring to one half. Mix until evenly colored.

Layer the fillings into the dessert glasses, starting with plain, then colored, and continue until filled.

Chill in the refrigerator for at least 2 hours.

Garnish with whipped cream, lime zest, or graham cracker crumbs before serving.