  Starting from kinetic theory, we obtain a nonlinear dissipative formalism
describing the nonequilibrium evolution of scalar colored particles coupled
selfconsistently to nonabelian classical gauge fields. The link between the
one-particle distribution function of the kinetic description and the variables
of the effective theory is determined by extremizing the entropy production.
This method does not rely on the usual gradient expansion in fluid dynamic
variables, and therefore the resulting effective theory can handle situations
where these gradients (and hence the momentum-space anisotropies) are expected
to be large. The formalism presented here, being computationally less demanding
than kinetic theory, may be useful as a simplified model of the dynamics of
color fields during the early stages of heavy ion collisions and in phenomena
related to parton energy loss.
