I hate to tell you this, but every time you watch television you are being duped. In fact there are only three accurate things you will ever see on television. These are the colours red, green and blue.
Each pixel on a screen can transmit three colours only. If blue alone is illuminated, the screen is blue. And it really is blue.
It looks yellow. But it isn’t really yellow. It’s a mixture of red and green light which hacks our optical perception so we think we are seeing yellow. That’s because humans, indeed all higher apes, are mostly trichromats. We have three different types of cones in the retina, each sensitive to a different part of the colour spectrum. It is from the contrasting signals received from these three types of cone that our brain reconstructs the visible spectrum. A TV needs only to be able to generate three colours in varying relative strengths to convince higher apes that the image is yellow — or lilac or brown. If you wanted to design a television for your dog, you could probably make do with just two colours per pixel. By contrast your pet parrot or tame bee (many birds and insects are tetrachromats, i.e. they have four types of cone) may look at your TV and wonder why dumb humans are happy to tolerate such an crappy, unrealistic picture.