P colonies were introduced in 2004 as a type of abstract computing device evolved from membrane systems—a biologically motivated computational massive parallel model. A P colony is composed of independent one-membrane agents, reactively acting and evolving in a shared environment. In this paper we summarize the results of computational power obtained for P colonies with bounded number of agents and programs; we reduce these parameters and we also add new results for so-called homogeneous P colonies with capacity two and one.