The screenshot of the amiga version above is just before the real colours kick in, the death of Alex sets the scene and the green is not visible until you have killed the first 4 enemies.
You know Alex? the missing character from the megadrive version?
Perhaps this is the screenshot you meant to paste?
And the megadrive version with missing golden axe and no sign of Alex doesnt need to set the scene, well, because there is no death scene to make more dramatic...
Notice the silver axe and drab washed out colours.