Colorization of packets displayed in the Packet List pane can be an effective tool to identify and highlight packets of interest, especially the packets that contain or indicate some kind of error condition.
Wireshark has predefined coloring rules that are enabled by default and which can result in a kaleidoscope of colored packets in the Packet List pane. You can enable or disable the coloring rules by selecting Colorize Packet List from the View menu or by clicking on the Colorize Packet List icon in the icon bar if this becomes overwhelming.
You can also view, enable/disable, add, delete, reorder, and edit the coloring rules by selecting Coloring Rules from the View menu or by clicking on the Edit Coloring Rules icon in the icon bar. There is a Clear button that removes all the changes you may have made to the rules and restores them to default settings if needed.
A Coloring Rules window is depicted in the following screenshot:
