Line a loaf pan with foil extending the edges all the way up the pan. Butter the foil and set aside.
In a 2 quart heavy saucepan, heat white chocolate and sweetened condensed milk over low heat. Stir constantly until chips are melted and mixture is smooth.
Remove from heat and pour half of the mixture into a small bowl.
Add lemon extract to half of the mixture and tint with yellow food coloring as desired.
Add lavender food coloring to the remaining half and tint with red and blue food coloring as desired.
Pour about half of the yellow into the prepared loaf pan, then about half of the lavender and then repeat with yellow and lavender.
Run a table knife through the mixture to swirl. Do not over mix, you want to swirl not blend the colors.
Add sprinkles to the top and gently press down.
Cover the loaf pan with foil or plastic wrap and place in the refrigerator to chill, at least 4-6 hours.
Lift the fudge out of the pan using the edges of the foil. Remove the foil and place on a cutting board. Slice into bite sized pieces. Store in a covered container.