As shown in the first screen snapshot below I got a new citizen that is assigned to the "Colonist" role. In the second screen snapshot, I do not see any benefit from being a Colonist. The third screen snapshot shows the roles to which I can assign a citizen that is currently a Worker and I do not see one named "Colonist".
Is the "Colonist" role just a placeholder indicating that the citizen has not been trained for a role yet? If not, what are the benefits of the "Colonist" role and why can't I train a citizen to be one?