Perception vs objective reality
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. But TV yellow is a big fat lie. 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