My point, which I'm not sure if you got so forgive me if you did, was that unless all your TVs have been 1-bit monochrome, each RGB pixel represents a 3D vector space all by itself. Your "3D" TVs are actually 7D!
And since we're being pedantic, white cannot both be "a color" and "all the colors" at the same time - in fact it's never "all the colors"! We are either using "color" as a shorthand for wavelength, in which case there's no such wavelength (yet merely 3 are sufficient to produce an impression of white, certainly not all of them), or "color" means the subjective impression produced, in which case the various shades of white comprise a narrow subset of these.
I can put white light through a prism and get multiple colours out. I made the assumption that actually white light contains all the colours, otherwise it would be off white. It's fair to assume that the whitish shade that eminates from a b&w TV is what is colloquially known as white. So I stand by my statement that a b&w TV contains all the colours.
I didn't think about colours being dimensions. They really are underselling TVs aren't they.
>I can put white light through a prism and get multiple colours out. I made the assumption that actually white light contains all the colours,
If you put the white light from your (color) TV through a prism, you will get precisely 3 colors out - red, green, and blue. That's hardly all of them!
>otherwise it would be off white
This is false! For any given subjective white point, there is an infinite set of wavelength triplets which will achieve it exactly. The white from an RGB display is perfectly good, not "off white" at all.
> It's fair to assume that the whitish shade that eminates from a b&w TV is what is colloquially known as white.
Not a valid assumption! The "phosphor" in monochrome displays can take a wide range of subjective colors - very often it's blueish[0]...
> So I stand by my statement that a b&w TV contains all the colours.
...and can have all manner of emission spectra [1]. There's no telling what you'll get if you put that through a prism! That being said, the entries in that table for B&W TVs do cover most of the visible range, so in the absence of spectral plots, I may be forced to give you this one...
Note it still doesn't reflect 100% of the light coming in which suggests it is still absorbing some wavelengths and so still isn't a perfect white.
So I assume you just aren't being pedantic enough when you say:
>The white from an RGB display is perfectly good
Remember, if someone sells you a black and white TV the black should be actually black, and the white should be actually white. If it's just blackish and whitish they're ripping you off.
And since we're being pedantic, white cannot both be "a color" and "all the colors" at the same time - in fact it's never "all the colors"! We are either using "color" as a shorthand for wavelength, in which case there's no such wavelength (yet merely 3 are sufficient to produce an impression of white, certainly not all of them), or "color" means the subjective impression produced, in which case the various shades of white comprise a narrow subset of these.
Did I mention I was pedantic? :)