  We study a system of few colloids confined in a small spherical cavity by
event driven molecular dynamics simulations in the canonical ensemble. The
colloidal particles interact through a short range square-well potential, which
takes into account the basic elements of attraction and excluded-volume
repulsion of the interaction among colloids. We analyze the structural and
thermodynamic properties of this few-body confined system in the framework of
the theory of inhomogeneous fluids. Pair correlation functions and density
profiles across the cavity are used to determine the structure of the system
and the spatial characteristics of its inhomogeneities. Pressure on the walls,
internal energy and surface quantities such as surface tension and adsorption
are also analyzed for the whole range of densities, temperatures and number of
particles considered. We have characterized the structure of systems from 2 to
6 confined particles as function of density and temperature, identifying the
distinctive qualitative behaviors all over the thermodynamic plane $T-\rho$ in
a few-particle equivalence to phase diagrams of macroscopic systems. Applying
the extended law of corresponding states the square well interaction is mapped
to the Asakura-Oosawa model for colloid-polymer mixtures. We link explicitly
the temperature in the confined square-well fluid to the equivalent packing
fraction of polymers in the Asakura-Oosawa model. Using this approach we study
the confined system of few colloids in a colloid-polymer mixture.

Soft Condensed Matter