Fair enough. I'm always amazed at the kind of tricks expert programmers could pull off on those old 2D machines.
Have you seen the Sega MegaColor demo? A crazy guy managed to play full color video at 30 fps in the Sega Megadrive. No graphics, no sprites, just change the background color for every pixel through DMA!
According to the information provided there, trying to do a 32-color full palette swap every scanline would starve the CPU.