1G A/C switch has 2 functions?

[Spades]

When i press the ac switch once the light turns yellow, when i press it again it turns green, a 3rd time turns it back "off". I assume green means "on" but what is yellow?

 

[Defiant]

The orange position allows the compressor to phase on and off, the green position keeps it running full-time. The orange is the "economy" setting.

 

[dgdsm]

Can the 1g a/c switch be swapped into the 2g heater control? The orange position is a nice little feature.