So I've been trying to make a pretty accurate clone of the good old Pokemon Yellow for quite some time now and one puzzling but nonetheless subtle mechanic has puzzled me. As you can see in the uploaded image there is a certain colour manipulation done in two stages after entering a wrap to another game location (such as stairs or entering a building).

One easy (and sloppy) way of achieving this and the one I have been using so far is to make three copies of each image rendered on the screen all of them with their colours adjusted accordingly to match each stage of the transition. Of course after a while this becomes tremendously time consuming.

So my question is does anyone know any better way of achieving this colour manipulation effect using java?

Thanks in advance,

Alex