No, that's just a normal 5 bitplane display mode with a copper trick. Real original 6 bpl HAM didn't need copper, it depended on current beam position left side pixel. For each pixel right side you could either set all RGB to one of 16 color palette OR modify red, green or blue value, but otherwise 'copy' left side pixel color.
So say you had white (15,15,15) pixel left side. Current pixel 'color'-data is "modify red 7", thus pixel becomes (7, 15, 15). Green and blue color components were held from left side pixel.
It was important to select those 16 paletted reset colors carefully for maximal effect. Otherwise you'd get a lot of ugly 2 pixel horizontal streaks when multiple color components changed from horizontal pixel to another quickly. You could of course use copper to change that 16 color palette for each scanline, too.
So say you had white (15,15,15) pixel left side. Current pixel 'color'-data is "modify red 7", thus pixel becomes (7, 15, 15). Green and blue color components were held from left side pixel.
It was important to select those 16 paletted reset colors carefully for maximal effect. Otherwise you'd get a lot of ugly 2 pixel horizontal streaks when multiple color components changed from horizontal pixel to another quickly. You could of course use copper to change that 16 color palette for each scanline, too.