  We investigate percolation in binary and ternary mixtures of patchy colloidal
particles theoretically and using Monte Carlo simulations. Each particle has
three identical patches, with distinct species having different types of patch.
Theoretically we assume tree-like clusters and calculate the bonding
probabilities using Wertheim's first-order perturbation theory for association.
For ternary mixtures we find up to eight fundamentally different percolated
states. The states differ in terms of the species and pairs of species that
have percolated. The strongest gel is a trigel or tricontinuous gel, in which
each of the three species has percolated. The weakest gel is a mixed gel in
which all of the particles have percolated, but none of the species percolates
by itself. The competition between entropy of mixing and internal energy of
bonding determines the stability of each state. Theoretical and simulation
results are in very good agreement. The only significant difference is the
temperature at the percolation threshold, which is overestimated by the theory
due to the absence of closed loops in the theoretical description.
