Meanwhile, in small saucepan over medium heat, combine 10 egg whites and sugar. Cook, stirring frequently, until egg whites reach 160°F. Remove from heat, transfer to electric mixer fitted with a whisk attachment. Beat egg whites on high until white and shiny and the bowl of the electric mixer is no longer warm, about 10 to 15 minutes. Add butter, one piece at a time, until mixture is smooth and shiny. If mixture separates, beat until smooth. Add raspberry preserves, vanilla and food color and mix until blended.