Process berries in a blender or food processor until smooth. Strain mixture into a small bowl, and discard seeds. Add the sugar and liqueur, and stir until sugar dissolves. This should make 1 cup of sauce.
In a heavy saucepan on low heat, warm 1/4 cup of the cream and the white chocolate, stirring constantly until chocolate melts. Let mixture cool until it is lukewarm. Stir in 1 tablespoon of raspberry sauce, and the food colouring. Transfer to a large bowl.
In a medium bowl, whip remaining cream to soft peaks. Fold into melted chocolate mixture, one-third at a time, until no streaks remain.
Layer into parfait dishes, and serve with the sauce.