Let's say I want to make the opacity of a JPanel %20 viewable? I don't mean setOpaque (draw or not draw) or setVisible (show or hide)... I mean make it see-through JPanel.. you know?
Is this possible?
panel.setBackground( new Color(r, g, b, a) );
You should also look at Backgrounds With Transparency to understand any painting problems you might have when you use this.