We can see that the Stadia controller is offered in three colours.
You can use the Stadia controller to play on any platform such as PC, mobile, tablet or TV. You connect it using Wi-Fi and Google intelligently detects which platform you're playing on.
The Stadia controller has an in-built Google Voice assistant button which lets you access Google's features while you're playing.
The controller also features a USB-C port on top and a 3.5mm headphone jack.