  Using high-speed confocal microscopy, we measure the particle positions in a
colloidal suspension under large amplitude oscillatory shear. Using the
particle positions we quantify the in situ anisotropy of the pair-correlation
function -- a measure of the Brownian stress. From these data, we find two
distinct types of responses as the system crosses over from equilibrium to
far-from-equilibrium states. The first is a nonlinear amplitude saturation that
arises from shear-induced advection, while the second is a linear frequency
saturation due to competition between suspension relaxation and shear rate. In
spite of their different underlying mechanisms, we show that all the data can
be scaled onto a master curve that spans the equilibrium and
far-from-equilibrium regimes, linking small amplitude oscillatory to continuous
shear. This observation illustrates a colloidal analog of the Cox-Merz rule and
its microscopic underpinning. Brownian Dynamics simulations show that
interparticle interactions are sufficient for generating both experimentally
observed saturations.
