Warm the fresh cream in a microwave (medium) for two minutes. Pour the dark and the white chocolate into separate bowls. Add half the warm cream to the dark chocolate and remaining to the white chocolate and mix well. Fold in half the whipped cream into the dark chocolate and remaining into the white chocolate. Mix well. Fill in two piping bags, one with dark chocolate mousse and another with white chocolate mousse. Take a glass ? small or big as per your choice. On one side pipe in dark chocolate mousse and on another side pipe in the white chocolate mousse. You can serve it at room temperature or chilled.