Button Colours?

My applications use a colour scheme for buttons to speed up training/familiarisation.  So Add is always a green button, Delete a red button and Edit is blue.  This theme is applied across the whole application so users look for green to save on every form.  Where you have several Adds or Edits the same colour will do as its not about different colours.  The purpose is consistency of colour/layout, i.e. Red is always a warning so you use it for close or delete.  Green is a go colour just like the Post button below (!).