Step 1In the bowl of a stand mixer using the whisk attachment, or in a large bowl with a hand mixer, beat together the cream cheese and butter until light and fluffy, about 1 minute. Add the sugar, lemon juice and peppermint extract and continue to beat until a consistent, smooth dough forms, 3 to 4 minutes.
Step 2Portion the mixture and knead in food coloring as desired. Press each portion into a flat disc, no more than one-half-inch thick. Wrap each disc tightly in plastic wrap and chill just until firm, about 1 hour.
Step 3Generously dust your work surface and hands with powdered sugar. Working with a few small pieces at a time (keep the remaining mint dough chilled until ready to use), roll the dough into one-third-inch-thick ropes and twirl or knead the colors together as desired. Cut the ropes into small pieces and transfer to a wax paper-lined baking sheet. Alternatively, roll about 1 teaspoon of the dough into a ball and then press a sugar-dusted thumb into the center to form flattened, round mints.
Step 4Set aside the mints, loosely covered with a sheet of wax paper, in a cool, dry place until they are dried on the outside and just slightly soft on the inside, 8 hours to overnight.