This advertisement will appear in Selected October Popular and GREEN Women's Weeklies, 1944 to start.. BLUE to win! Why are there differences in the food allowances and priorities when a child reaches 5 or 6? Because by that time — thanks to the good start you've given him with the green ration book "extras" —he will have developed a set of strong little teeth and a healthy digestive system capable of dealing with the same kinds of meals as the rest of the family. So he changes to the blue book, and becomes entitled to full adult allowances of all rationed foods and, because he is still growing, to a certain priority on milk, too.