In a small bowl combine 1/2 cup candy melts and 3 tablespoons plus 2 teaspoons sweetened condensed milk. Microwave on 100% power (high) for 30 seconds and stir until smooth. To make the purple layer, stir in 4 drops each of red and blue food coloring and 1/8 teaspoon orange extract. Drizzle evenly into bottom of prepared pan and spread smoothly using a small offset spatula. Chill 5 to 10 minutes until soft set. Repeat layers, using 1/2 cup candy melts, 3 tablespoons plus 2 teaspoons condensed milk, food coloring, and 1/8 teaspoon orange extract in each layer. (For blue use 8 drops food color; for green 8 drops food color; for yellow 8 drops food color; for orange use 4 drops each red and yellow food color; and for red use 16 drops food color.) Drizzle each mixture over the soft set layer in pan, then spread to edges. Chill layers 2 hours or until firm.
Use foil to lift uncut fudge from pan; remove foil. Cut fudge into 1-inch squares and store in an airtight container in the refrigerator up to two weeks.