Visibility of particle specie, type (primary, true secondary, or back-scattered), generation and entry/exit attribute name can be toggled via the light bulb icons in the Browser. This can be helpful for removal of visual clutter. You can also control the number of particles and the number of positions (knots) per particle shown. Coloring can be changed, for example to highlight features for presentations or to allow tracking of the path of a specific particle. For further discussion, and a worked-out example, see here.