preventing lead separation under thermal expansion

What does the green color code signify on these controls

This model is constructed from lead-free materials to comply with federal regulations for potable water systems

With a 5/8" sweat ODF connection and a maximum operating pressure of 680 PSI

Lennox 66J78 Limit Switch Els PW 17895 preventing lead separation under thermalExperienced HVAC contractors recognize the Lennox 66J78 Limit Switch as a critical safety component for maintaining furnace integrity and preventing heat exchanger damage. This OEM Lennox replacement part is a 36T series disc style control designed for High Limit or Secondary Rollout applications. It features a Normally Closed (NC) circuit that opens on temperature rise to interrupt the heating cycle if internal temperatures exceed safe operating