  We present a phenomenological theory of scalar particles that transform as a
sextet and an octet of QCD interactions. These particles may arise as light
bound states of a fundamental dynamics giving rise to a composite Higgs boson
and partial compositeness for the top. As a concrete example, we discuss an
explicit UV completion based on the SU(4)/Sp(4) coset, where QCD colour is
carried by additional fundamental fermions charged under the confining gauge
group. Top partners, as well as potentially even lighter coloured scalars,
arise as bound states of the coloured fermions. We study production and
detection at LHC Run I and II of the octet and sextet, setting lower limits on
masses and couplings to Standard Model particles using existing 8 TeV analyses.
We finally explore prospects for the ongoing 13 TeV Run II: we focus on final
states with two same sign leptons, that have the potential to discriminate the
sextet.
