Evergreen Fog and Retreat (SW 6207) have similar undertones (Retreat has deeper gray undertones), but its LRV of 21 makes Retreat appear much darker and less colorful than Evergreen Fog.
They both belong to the same family but have some big differences.
Clary Sage leans warmer thanks to some strong yellow undertones.
Evergreen Fog is the color you want when you crave a restful retreat or neutral and toned-down pop of color.