That is correct, a "dull coat" is a cleat flat (matt) finish.
I will add another consideration. When applying your main colour coats, if you are applying a multi-colour camoo scheme, the general rule of thumb is to apply the lighter colour first and then darker colours over it. This prevents "show through" (unless you have some reason to allow it) as it's much easier to cover a light colour with a dark colour than it is to do the reverse.