Make "z" a keyword

[Voidymite]

Is your feature request related to a problem?

The pair "x, y, z" all having the same color would be more appeasing. In the context of "keyword" I moreso mean how the variables "message" and "longMessage" are—they're green like the "x" and "y" variables but do not do anything special

Describe the solution you'd like

Turn the letter z into a keyword variable.

Describe alternatives you've considered

No response

Additional context

In summary what I would like to see in the coming future is something similar to this:

[stuckie]

'z' is not a built-in instance variable