protected void actualizarMuestraObjeto() {
    int r = (int) spinObjRed.getValue();
    int g = (int) spinObjGreen.getValue();
    int b = (int) spinObjBlue.getValue();

    Color c = new Color(r, g, b);
    lblObjMuestra.setIcon(new ImageIcon(new ImgMuestra(c, 80, 80)));
    panelImagen.setObjectColor(c);
  }