Gracious, and seasoned with salt

"Salty speech" today means something crude. That is not what Paul means. Salt here is positive, and the aim he gives is knowing how to answer each person.
It belongs with discipleship and with being like Jesus in the way you treat people. And "outsiders" is not a sneer - Paul has just been speaking about the mystery, that the Gentiles are being brought in.
Scripture links:
- Colossians 4:5-6 - "Walk in wisdom toward outsiders... Let your speech always be gracious, seasoned with salt, so that you may know how you ought to answer each person."
- Colossians 1:27 - The mystery he has in view: Christ in you, among the Gentiles.
The people outside are not the enemy. Speak to them like someone who was once outside too.