in src/main/java/idea/plugin/psiviewer/util/Helpers.java [71:86]
private static Icon getDefaultIcon()
{
BufferedImage bi = new BufferedImage(18, 18, BufferedImage.TYPE_INT_ARGB_PRE);
Graphics2D g2 = bi.createGraphics();
g2.setBackground(Color.red);
g2.clearRect(0, 0, bi.getWidth(), bi.getHeight());
g2.setColor(Color.white);
g2.setStroke(new BasicStroke(2));
GeneralPath x = new GeneralPath();
x.moveTo(0, 0);
x.lineTo(bi.getWidth() - 1, bi.getHeight() - 1);
x.moveTo(0, bi.getHeight() - 1);
x.lineTo(bi.getWidth() - 1, 0);
g2.draw(x);
return new ImageIcon(bi);
}