Good question! The orange light indicates that the switches are running Spanning Tree Algorithm (STA). This is a normal process. What is STA? It is a layer 2 bridging protocol that allows switches to be physically connected into a loop without suffering from broadcast storms. IP limits loops by using the TTL field, however, there is no method to limit loops within Ethernet. STA adds that functionality. Upon startup, each switch sends out a special type of frame to select the root bridge for the network.
This was first published in November 2002