  We study the behavior of negatively charged colloids with two positively
charged polar caps close to a planar patterned surface. The competition between
the different anisotropic components of the particle-particle interaction
patterns is able by itself to give rise to a rich assembly scenario: colloids
with charged surface patterns form different crystalline domains when adsorbed
to a homogeneously charged substrate. Here we consider substrates composed of
alternating (negative/neutral, positive/neutral and positive/negative) parallel
stripes and, by means of Monte Carlo simulations, we investigate the ordering
of the colloids on changing the number of the stripes. We show that the
additional competition between the two different lengths scales characterizing
the system ($i.e.,$ the particle interaction range and the size of the stripes)
gives rise to a plethora of distinct particle arrangements, where some
well-defined trends can be observed. By accurately tuning the substrate charged
motif it is possible to, $e. g.,$ promote specific particles arrangements,
disfavor crystalline domains or induce the formation of extended, open
clusters.
