Every year Supercell participates in the (PRODUCT)RED charity event that fights against AIDS and other diseases in poor countries all over the world. This is an Apple exclusive event, so all of you using Android won’t see this since Google doesn’t participate. All the revenue generated from the in-app purchases of RED products will be donated to charity at the end of the event.
It’s a non-mandatory update in the AppStore and you will see the RED products in the shop of the game.
In fact, the deals are nice if you want to buy the gems anyway.
If you plan on buying a Pile of Gems please consider choosing the RED-one, because all the money generated gets donated to charity. In addition, you get gems like you always do.
Remember, this is an Apple event and all of you playing on Android are not able to participate. Beside the red patch on the decoration, there is no gameplay-related change.