I expect you are correct. The Amiga (except some early 1000s) also had a Extra Half Brite mode that has 6 bitplanes, 64 colours with the second 32 being half t

I expect you are correct. The Amiga (except some early 1000s) also had a Extra Half Brite mode that has 6 bitplanes, 64 colours with the second 32 being half the brightness of the others. https://en.wikipedia.org/wiki/Amiga_Halfbrite_mode https://en.wikipedia.org/wiki/Amiga_Halfbrite_mode The extra data fetching does slow things down. https://eab.abime.net/showthread.php?t=102990#:~:text=And%20unlike%20the%20double%20playfield,brite%20mode%20is%20very%20slow https://eab.abime.net/showthread.php?t=102990#:~:text=And%20.... The panel at the bottom looks like it uses the copper to have a different palette to the rest of the screen. That is a very common effect. https://codetapper.com/amiga/sprite-tricks/shadow-of-the-beast/ https://codetapper.com/amiga/sprite-tricks/shadow-of-the-bea...