public void setStyle(int start, int end, int style) {
        letters.setStyle(start, end, style);
    }
Set the font style of substring. If font doesn't contain style, default style is used
@param start start index to set style. inclusive.
@param end   end index to set style. EXCLUSIVE.
@param style the style to apply
jme3-core/src/main/java/com/jme3/font/BitmapText.java