As the quarks move apart, in frames 5 and 6, a color force field develops between them. The energy in the force field increases with the separation of the quarks. In frame 7, the u quark and the strange antiquark begin to separate. 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.
Meson Chart Quarks Quark Interactions Quark Confinement See all ten frames of this picture together.