What is a FosterClub YellowBox care package? A YellowBox can brighten a child’s day... It’s a gift that comforts kids in America's foster care system to know they are not alone. Choose to send your YellowBox in honor of a friend or family member (what a great way to tell someone they’ve inspired a gift to children!) and we’ll send an email or mail a card announcing the gift. What will you include in your YellowBox?