code: private void setupRTFXSpecificCSSShapes() {
          String background = "-rtfx-background-color: red; ";
          String underline = "-rtfx-underline-color: blue; " +
                  "-rtfx-underline-width: 2.0;";
          String border = "-rtfx-border-stroke-color: green; " +
                  "-rtfx-border-stroke-width: 3.0;";
  
          // set all of them at once on a give line to insure they display properly
          area.setStyle(0, background + underline + border);
  
          // set each one over a given segment
          area.setStyle(1, 0, 3, background);
          area.setStyle(1, 4, 7, underline);
          area.setStyle(1, 8, 11, border);
      }
docs: Shows that RTFX-specific-CSS shapes are laid out in correct order, so that
  selection and text and caret appears on top of them when made/moved