Ok, I know this is not really a photography thing, but asis used, I may get some help anyway.
In this day and age, we seem to resolve things down to 3 colours. Red, Green and Blue.
Though when I was at school I am sure Yellow was in there somewhere and Green wasn't, well in painting anyway.
So with "RGB" and electronics we can make an colour we want which is why televisions use those three colours.
These are called PRIMARY colours - dur.
There is a thing called a photo-spectrometer (spelling) which basically has a prism and you get a "colour map" (or what ever it is really called) with black lines indicating a unique colour signature for that specific colour. Yeah, ok, badly explained, but it is only 07:20 and I am trying to get this sent off before I start work.
Maybe for simpicity's sake they say the colour is broken down into THREE colours, which is why I am confused - because:
Recently I learnt that the rainbow has SEVEN colours. That is a bit more than three.
Is this why there are some expensive printers which have seven colours as opposed to the typical 4 (CMYK)?
I understand a bit how RGB and CMY are related. One is for electronic referene and one is for printing. R+G+B = white. C+M+Y = black.
I've forgotten the pairing of the colours, how R = C+M (for example) or C-M.... What ever.
Could someone help me understand a bit more about what is going on with the actual colours, how many are "claimed" to exist/are needed and that kind of stuff.
Yeah, sorry for the vagueness, but I don't quite undertand the bigger picture myself, so it is difficult to ask the question in a sensible way.