  We observe that the linear potential used as a leading approximation for
describing color confinement in the instant form of dynamics corresponds to a
quadratic confining potential in the front form of dynamics. In particular, the
instant-form potentials obtained from lattice gauge theory and string models of
hadrons agree with the potentials determined from models using front-form
dynamics and light-front holography, not only in their shape, but also in their
numerical strength.
