As the quarks move apart, a color force field develops between them. The up and antistrange quarks begin to separate. All the quarks have formed color neutral pairs. Each such decay yields a set of color neutral particles made from the quarks that materialize from the energy in the color force field.
Many different outcomes are possible.
The intermediate stages of this process occur in less than almost a billionth of a billionth of a billionth of a second, and are not observable.