All computers that use the Motorola 6847 Video Display Generator(VDG) have the same colour set. Re guardless what the marketing and/or manuals/Data Sheets say.
In North America this includes the TRS-80 COCO, APF Imagination Machine, Dragon by Tano, NEC Trek and VZ 200.
Note: CSS = Palette Select
|CSS0 Text||Green and Black||Actually its two intensities of Green||GREEN||"BLACK"|
|CSS1 Text||Orange and Black||Again actually two intensities of one colour.||ORANGE||"BLACK"|
|Semigraphics||Selection of 8 colours.||All OFF pixels in this mode are Black.||OFF Pixel||ON Pixel|
|BUFF||Almost but not quite WHITE|
|Color Graphics||Four Colors CSS0||Green, Yellow, Blue, Red|
|Color Graphics||Four Colors CSS1||Buff, Cyan, Magenta, Orange|
|Resolution Graphics||2 Colors CSS0||Green and "Black"||OFF||ON|
|Resolution Graphics||2 Colors CSS1||Buff and Black||OFF||ON|
I'm guessing that in 1975/6 most colour TVs and many monitors could not show that low level of Green over Black. However, I doubt that the dark Orange ever showed as Black on any colour monitor.
You may notice that IF you inclued the 'BLACK' Text colour in with the Semigraphics, you actually get 10 colours on screen.
Eg: BLACK, TEXT BLACK(Dark Green), GREEN, YELLOW, BLUE, RED, BUFF, CYAN, MAGENTA, ORANGE
The APF and NEC Trek can change CSS on screen thus getting all 8 colours in Color Graphics modes and 4 colours in Resolution Graphics modes.
The TRS-80 COCO, Dragon by Tano and VZ 200 can only display 4 colours in Color Graphics and 2 in Resolution Grpahics modes.