The color scheme is blindingly bright.
If you update your photo for Chat, it's updated for other Google services.
The easiest way to tell if a conversation is using old-fashioned text messaging or the new chat features is to look at the text box before you start typing.
Google's Chat features make texting between compatible phones a breeze, especially if you aren't sure whether your friend or family member uses another service such as WhatsApp, Signal, Telegram or another texting app.
Just follow the prompts and don't worry, you won't lose your conversation history by switching.
Because Chat works over mobile data or Wi-Fi, you can put your phone in airplane mode and you'll still be able to send and receive messages with other Chat users using only a Wi-Fi connection.
That's an important aspect of Chat.
To know how to do these things, you can visit the official.