I’m only going to add a few comments here — since you’ve already managed to remedy the problem — both for your own education and for that of anyone stumbling upon this thread. 
That is the default appearance of the prompt for zsh if no customization has been applied.
This default you are referring to is the Manjaro-applied theming of the zsh prompt, not the zsh default. 
A tty is not a GNOME Terminal — not by a million light-years. It doesn’t have anything to do with GNOME or whatever other graphical user interface.
GNU/Linux is a UNIX operating system, and at its heart, UNIX is a character-mode operating system that allows users to interact with the system by way of a command line.
Given however that UNIX was designed from the ground up as a multiuser operating system with concurrent access by multiple users at the same time, it has to define interfaces through which these users can access the system.
These interfaces are called terminals, and up until the 1990s — and in some cases, even up to this very day — these terminals were separate devices that looked like slim desktop PCs, with a CRT monitor and a keyboard, and that were originally connected to the main computer by way of the serial ports on the computer’s motherboard. In times even longer gone, these terminals were actually teletype machines, without a screen and without any possible distinction between upper- and lowercase characters.
Nowadays, people interact with multiuser servers (such as mainframes) by way of terminal emulators, which are software-based, rather than hardware-based, and with the hardware connection being via UTP cabling. GNOME Terminal, Plasma’s Konsole and the likes are such terminal emulators, but specifically designed to connect to the underlying UNIX system on the local machine, rather than to a remote machine — there exist other and much simpler ways for doing that, such as a remote shell connection via ssh.
Given that the hardware for the x86 platform and other microcomputers such as the Macintosh was designed as inherently single-user, the Linux kernel has to work around this crippled hardware for offering multiuser functionality.
As such, the default Linux console — i.e. the terminal infrastructure in the kernel through which boot-time messages are displayed on the (primary) screen and the keyboard through which the system administrator can interact with the system — has to be set up to emulate a set of multiple virtual consoles. These virtual consoles are what we refer to as a tty — the name tty itself is a historical reference to the use of teletype machines as computer terminals.
Therefore — and long story short — a tty doesn’t have anything to do with the in UNIX optional graphical interface. A tty is just one of several character-mode virtual consoles through which the multiuser UNIX operating system can interact with the inherently single-user hardware console, which itself consists of the graphics adapter and monitor, the keyboard and the (in character-mode optional) mouse.
You’re welcome.