Twitter Blue comes with Color Themes as well as custom App Icons.
However, this service is not yet out in India but is listed in UK and USA.
Manchun Wong has become the first Twitter blue customer after purchasing the service.

Even theapp iconcan be changed to pink, purple, green, orange, and more colors.
Even there will be an option of Undo tweets, which is one of the most requested features.
Undo Tweet feature was spotted in March, and again its seen here as well.

There are details on when this service will be public.
The in-app purchase option is seen in Apple App Store and it might soon be available for all.
This service will help the app to increase its revenue as people will pay to use its additional features.

