It is to notice that if the Amstrad CPC could have a 320x200x16 mode... the dithering possibilities would have been quite awesome, and the palette would be more than well exploitable on the best 8bit Graphic machine...
As shown... the CPC original palette is good as it enable gradiants in Black and White + 3 shades for the 6 basic colours...
Red, Green, Blue... and Yellow, Cyan and Magenta (purlple).
Added to those, there are a few special crossbreed colours such as Mauve (2 shades : mauve and Pastel blue), orange (can mix with red and yellows), Purple (a bluer Red) and a lot of "light greeens" (turning into Cyan or yellow).
Yet those are saturated colours, not fit for Greys or Brown spectrums as the C64 palette was. still great for comics styled graphics.
*the cubic nature of the CPC palette