Telephone numbers are there to be called. You don't get very far here in Panama with letters in letterboxes…
The colours of the letterboxes and the number of letters they contain play an important role. Mr. Jackson emphasises the words SUN, SKY, CRIMSON and FIELDS on the telephone. Exactly the colours of the letterboxes…
The correct four-digit code is: 1394 (the number of letters in the letterboxes in the order yellow, blue, red, green).
Mr. Jackson gives you the last puzzle on the telephone. A little hint: they speak Portuguese in this country.