Cabletron Systems 7C03 User Manual page 139

Using the 7C0x SmartSwitch Bridge View
When you disable a Transparent bridge port, the port's display box turns blue.
When you enable a Transparent bridge port, the port's color changes to indicate
the forwarding threshold range. (Port color codes are only active if the Color box
is selected in the Forwarding Thresholds window. Color codes are on by default.)
Enabling and Disabling Ports 6-37