  The Standard model of particle physics provides a successful theory to
understand the experimental results of the electroweak and strong interactions.
However, it does not have a satisfactory explanation for the hierarchy problem.
Many extensions of the Standard Model that solve the hierarchy problem result
in new particles. We will study the phenomenology of vector-like fermions
resulting in theories where the Higgs boson is typically a
pseudo-Nambu-Goldstone boson. In these theories we study the case where a heavy
fermion will be heavier than a heavy gluon, and then the channel of a heavy
fermion decaying into a color octet is considered. We study this phenomenology
at high energy colliders, both the LHC as well as future machines.
