printList will take a nested list of unknown depth and print each item on a separate line.

printlist.js

// Proposed solution for an exercise given to a friend: http://pastebin.com/hjFCZYE7

function printList(linePrefix, list) {
  for (var i = 0; i < list.length; i++) {
    if (typeof list[i] === 'string') {
      console.log(linePrefix + '.' + i + ': ' + list[i]);
    } else {
      printList(linePrefix + '.' + i, list[i]);
    }
  }
}


var sample = ["Red",["Yellow","Green","Blue"],"Black",[["Orange","Purple"],"White"]];
printList('Test', sample);