In Racket, how to get and set an object's field as if it was a local variable?

In Racket, how to get and set an object's field as if it was a local
variable?

I want to do something like this:
(define-field-magic color car)
(set! color "green")
(pretty-display color)
Instead of this:
(set-field! color car "green")
(pretty-display (get-field color car))