See also: Guest
Red color used to be the normal chatting color a long time ago, it was used when Tankster.io was still in Alpha and was called arrasio.me:3000 (in 2019). It was changed a long time ago to the white that you all know and love.
At the very beginning, the chat used to appear above the player who sent the message's tank. But it was moved to the left side of the screen. The messages also had rounded corners instead of the pointy ones that are used today.