The way a computer screen uses pixels to display images

Your fancy high-def screen is really just a massive, glowing cross-stitch kit. If you look close enough, there is no actual image—just millions of tiny, stubborn lightbulbs called pixels, all squashed together like sardines in a tin.

Each pixel is a lazy thing, only capable of glowing red, green, or blue. It is like trying to paint a masterpiece using only three buckets of paint. By flickering at different brightness levels, these three colors trick your eyes into seeing a full spectrum.

It is a ridiculous amount of faff just to show a cat video, but that is the magic trick. Your brain does the heavy lifting, blending those three tiny lights into a single color while the screen just sits there glowing.

Wait, if there's no yellow bulb, how on earth am I seeing a banana?

It’s a bit of a cheeky optical illusion, like a seaside stall selling 'crab' sticks that have never seen the ocean. You aren't seeing yellow light; your brain is just being lazy and averaging things out.

When red and green pixels glow at full blast together, your optic nerves get in a muddle. They send a combined signal that your brain translates as yellow.

It’s the ultimate shortcut. By tweaking the 'volume' of those three colors, the screen fakes millions of shades without needing extra buckets of paint.

Does that mean white light is just all three bulbs screaming at once?

Exactly! To get white, you just crank all three bulbs to their absolute limit. It’s like a seaside choir where everyone is shouting; from a distance, you can't hear the notes, just a bright wall of sound.

Your eyes can't distinguish the individual colors anymore, so they throw in the towel and label it 'white'. It’s a clever bit of corner-cutting by the screen.

If you want black, the pixels simply do nothing. They sit there as idle as a deckchair in a storm. No light, no effort—just darkness.

But if the pixels are off, why is there still a faint glow?

That’s the catch! Most screens are like a house with a massive floodlight shining through the back window. Even when you pull the heavy curtains—the pixels—to make it 'black,' a bit of light always leaks through the stitching.

Unless you’ve spent a fortune on those fancy OLED screens, your 'black' is really just a very dark, moody grey. It’s like trying to hide a lighthouse with a bedsheet; you’re never going to get total darkness.

It’s a right old faff. The screen is working overtime to block light that it’s simultaneously generating right behind itself. Absolute madness, really.

What makes those posh OLED screens so special then?

OLED is the clever bit of kit where we finally binned that giant floodlight. Instead of one big light at the back, every single pixel is its own tiny, independent lamp.

It’s like giving every person in a seaside parade their own torch instead of relying on a lighthouse. When a pixel needs to be black, it doesn't just close a curtain; it literally switches itself off and goes to sleep.

No light, no leakage, no faff. You get a black so deep it’s like looking into a coal cellar at midnight. It’s much more sensible, even if it does cost a pretty penny.