  Correlators of Wilson-line operators in non-abelian gauge theories are known
to exponentiate, and their logarithms can be organised in terms of collections
of Feynman diagrams called webs. In [1] we introduced the concept of Cweb, or
correlator web, which is a set of skeleton diagrams built with connected gluon
correlators, and we computed the mixing matrices for all Cwebs connecting four
or five Wilson lines at four loops. Here we complete the evaluation of
four-loop mixing matrices, presenting the results for all Cwebs connecting two
and three Wilson lines. We observe that the conjuctured column sum rule is
obeyed by all the mixing matrices that appear at four-loops. We also show how
low-dimensional mixing matrices can be uniquely determined from their known
combinatorial properties, and provide some all-order results for selected
classes of mixing matrices. Our results complete the required colour building
blocks for the calculation of the soft anomalous dimension matrix at four-loop
order.
