docs: function customize(bitmap) {
      const size = bitmap.size;
      const data = bitmap.data;
  
      for (let x = 0; x < size; x++) {
          for (let y = 0; y < x; y++) {
              const offset = coord2offset(x, y, size);
              // If it's white change it's color
              if (data[offset]) {
                  data[offset] = 255 - Math.abs(x - y);
              }
          }
      }
  }