  The classical Yang-Mills equation of motion is numerically investigated in
the Lorentz gauge for a SU(2) gauge group. The color-electric field of two
point-like charges is studied in the ''empty'' vacuum and in a state with an
instanton present. The major effect for a fixed orientation of the instanton is
that the color-electric field lines are expelled or attracted from the
instanton region depending on the orientation of the instanton. If over the
orientations of the instanton is averaged, this effect drops out. In this case
of a random instanton orientation, we find that the external color-electric
field is expelled from the instanton core. The origin of this effect is
discussed.
