This ingenious idea solves the perpetual struggle of young/inexperienced/lazy shoppers and also makes use of the common fruit sticker! 

Certain fruits are common enough for shoppers to figure out their ripeness from color and texture, such as apples and bananas. However, other fruits that are less common or have a drastically different skin are much harder to tell. Avocado is notorious in that regard, which is why the tri-color label is so helpful in determining whether it is time to purchase. Similarly, mangoes come in different varieties. The stickers can indicate for a particular type of mango when is the best time to enjoy a ripe fruit!