Active elements are the elements a simulation session is focusing on (see Understanding simulation sessions for more information). They can also be considered as the elements that are currently being simulated in a simulation session. They will be annotated with red (by default). Once an active element has been simulated, it will become a visited element and will be annotated with green by default (see the following figure). The last visited element will be annotated with orange (by default).
Figure 1: Animation: Active Element in Red, Last Visited Element in Orange, and Visited Elements in Green