code: function getColor (i) {
      i = parseInt(i);
      if (i < 0 || i >= colors.length) {
        // pick a color from the scale defined above
        return scale(((i - colors.length) * (211 / 971)) % 1);
      } else {
        return chroma(colors[i]);
      }
    }
docs: Get i-th color
  @param {number} color number
  @returns {Object} color