The Versatile Banana by Miriam Lane (in a 1940s issue of Modern Woman), covers how to bake, broil, and fry bananas; provides recipes for Banana Fritters, Ham Banana Rolls, Banana Spice Layer Cake, and Tomatoes Tropical; and banana basics.
Bananas are yellow-ripe when the green has disappeared from the tip...
Fully ripe bananas are golden yellow flecked with brown. Now in its prime, the banana has reached the best stage for eating. Sweet, mellow and thoroughly digestible, it's just right for fruit cups salads, desserts and beverages.
Interestingly, this article considers the banana -- or the not fully ripe banana -- to be a vegetable:
Yellow bananas tipped with green are partially ripe. The pulp is firm, starchy, slightly tart, and just right to cook and serve with the main course as a vegetable.