Starray is a Defender clone, but most famous for its awesome digitized theme song. But it's also interesting for its graphics.
While the Amiga version featured modern/futuristic visuals done by Andreas Voigt and Arno Seiler, the Atari-ST featured completely re-done graphics done by veteran artist Pete Lyon in a more retro/modern style.
It seems like Pete created the graphics for the Atari-ST version by using the Amiga version as reference, since both versions feature the same themes, but he added his own twists and style and in the end came out with the better result.
It's still apparent, that the game is struggling with the technical limitations of the Atari-ST by only having 16 colors available and some levels (like the cave level) only allocating 5 colors to the backdrops.
The Atari ST version also pre-calculated horizontal scrolling by storing the backgrounds in 16 instances (each scrolling horizontally by one pixel), because it lacked the hardware scrolling that the Amiga could do.
This worked nicely, but used up a lot of memory, leaving less space for graphics, and that's why the Atari ST backgrounds loop more frequently.
The copper was used to switch the color registers between the logo and the rest of the image. Nearly all palette entries are changed, except the orange background colors which have to remain the same between both palettes so that the switch doesn't get noticed.
Same background but different spaceship. There are no visible artifacts and the previously obscured explosion looks coherent to the rest of the style. I think it's highly likely that this was an earlier artwork from Arno.
Original title art for Starray on the Atari-ST by Pete Lyon. It looks like this may have been inspired by the variation of the title screen, since the spaceship is flying in the same direction and also has similarly double-angled wings.