code: void fillOutsideAreas(int color, Rectangle insideArea) {
          this.canvas.setClipDifference((int) insideArea.left, (int) insideArea.top, (int) insideArea.getWidth(), (int) insideArea.getHeight());
          this.canvas.fillColor(color);
          this.canvas.resetClip();
      }
docs: Fills the area outside the specificed rectangle with color.
  This method is used to blank out areas that fall outside the map area.
  
  @param color      the fill color for the outside area
  @param insideArea the inside area on which not to draw