This is a Final Fight arcade graphics conversion test to 16 colors.
In the attachment there is an ADF with a demo, so that you can see this actually running on an A500.
Here's a screenshot of the end result:
So, what I did here is that the characters were converted to 14 colors, leaving two colors for the copper. And then the sky, the building and the street were colored with those 2 copper colors.
Only the beginning of the level is there, but the coppers are designed in such a way, that the full level could be done in this way. And the sky copper color is still "free" in the space between the windows and the street, so it can be used for the trashcans and other stuff that would come later in the level.
And even if the coppers wouldn't be enough, the palette itself can handle many things on it's own.
This was just a quick test, so it's not 100% perfect, a few things could still be made better. But it gives a good idea of what the 16 color mode + copper is capable of. 52 colors on screen and looks about as good as the arcade version. And most importantly, the characters stand out really well from the backgrounds.
Demo is made with Blitz Basic 2 and running speed is 6 or 7 characters at 25 FPS. Brute force redraw is used, so it's a screen sized Blockscroll + blits. However, in this demo the Blockscroll doesn't follow the actual scroll (didn't bother to make it so, because I'm not doing the whole level), so you'll see some glitches at the right side of the bitmap. But just press space to clean the screen.
I'l later post some images on how the screen looks without the coppers and on so.