# How do we see color?

An episode of [Science for Kids / Science's Not Boring: The Kids Science Podcast](https://invisiblenetwork.ai/podcast/1896928296), 19 Aug 2026, 14 min.

Audio: https://www.buzzsprout.com/2624612/episodes/19635348-how-do-we-see-color.mp3

Did you know that the bright red of a shiny apple or the vibrant green of the grass doesn't actually exist outside your head?! It is completely made up by your brain! Join Mira and Finn on a mind-blowing journey to find out how your eyes catch incredibly fast waves of light to create the beautiful world around you! You will discover how Isaac Newton trapped a rainbow inside his bedroom, and learn all about the millions of microscopic light-catching cells hiding inside your eyeballs called rods and cones! But wait, do animals see the same rainbow we do? Prepare for some wild surprises! You'll find out why you should never throw a red toy for your dog, how bumblebees use secret invisible light to hunt down sweet flowers, and meet a super-powered underwater superhero! The Peacock Mantis Shrimp has 16 different color catchers and punches its prey as fast as a car! Packed with amazing fun facts, a colorful trivia quiz, and the shocking truth about the color pink, this episode will change the way you look at the world forever!

## Transcript

[0:46] SPEAKER_00: Welcome to Science is Not Boring by Codopoly.com.
[0:49] SPEAKER_00: I'm Mira.
[0:50] SPEAKER_00: And I'm Finn.
[0:52] SPEAKER_00: Get ready, Finn, because today we are absolutely blowing your mind.
[0:57] SPEAKER_00: I want you to imagine looking at a bright, shiny red apple.
[1:02] SPEAKER_00: Okay, I'm picturing a delicious red apple right now.
[1:06] SPEAKER_00: Well, prepare yourself for this.
[1:09] SPEAKER_00: That red colour?
[1:10] SPEAKER_00: It doesn't actually exist outside of your body.
[1:14] SPEAKER_00: Colour is an illusion, entirely made up inside your head.
[1:18] SPEAKER_00: Wait, wait, wait, what?
[1:20] SPEAKER_00: You're saying everything I see is fake?
[1:24] SPEAKER_00: The light bouncing off the apple is very real, but the colours you see are basically a translation that your amazing brain invents to make sense of the universe.
[1:35] SPEAKER_00: That is literally the wildest thing I have ever heard.
[1:38] SPEAKER_00: I know! Today we are going on a journey to find out exactly how your eyes catch light, why some people see colours completely differently, and why a tiny little bee sees a totally different version of the world than you do.
[1:53] SPEAKER_00: To understand the magic of colour, we have to start by talking about light.
[1:57] SPEAKER_00: Light travels through space in tiny invisible waves.
[2:01] SPEAKER_00: Like ocean waves crashing at the beach.
[2:04] SPEAKER_00: Sort of, but unimaginably faster.
[2:08] SPEAKER_00: Light zooms through space at a speed of 186,282 miles per second.
[2:15] SPEAKER_00: Whoa, 186,000 miles per second! That's fast enough to zoom all the way around the entire Earth seven and a half times in one single second.
[2:26] SPEAKER_00: Exactly! Now, back in the year 1666, a famous 23-year-old scientist named Isaac Newton proved something incredible about this light.
[2:38] SPEAKER_00: Wait, Isaac Newton.
[2:39] SPEAKER_00: The gravity guy who watched the apple fall from the tree.
[2:43] SPEAKER_00: The very same guy! He was staying home from Cambridge University because of the Great Plague.
[2:48] SPEAKER_00: He sat in his darkened room and bored a tiny quarter-inch hole in his window shutters to let a single beam of white sunlight inside.
[2:57] SPEAKER_00: And then what happened?
[2:59] SPEAKER_00: Did he put something in the way of the beam?
[3:01] SPEAKER_00: He placed a triangular piece of glass called a prism right in the path of the beam.
[3:06] SPEAKER_00: The white sunlight went in, and a massive, brilliant rainbow burst out across the wall.
[3:12] SPEAKER_00: No way! He made his very own rainbow inside his bedroom.
[3:17] SPEAKER_00: Yes! He proved that pure white light isn't just empty.
[3:21] SPEAKER_00: It is actually made of all the colours of the rainbow mixed perfectly together: red, orange, yellow, green, blue, indigo, and violet.
[3:32] SPEAKER_00: So when that white sunlight hits that shiny red apple, what exactly is happening on the apple's skin?
[3:38] SPEAKER_00: The apple skin acts like a sponge for light.
[3:41] SPEAKER_00: It absorbs almost all the colour wavelengths.
[3:45] SPEAKER_00: It sucks up the blue, the green, and the yellow.
[3:48] SPEAKER_00: But it rejects the red waves.
[3:50] SPEAKER_00: Ah, so the apple bounces the red light back into the room like a tiny fruity mirror.
[3:56] SPEAKER_00: You got it! The apple isn't creating red light.
[4:00] SPEAKER_00: It's just throwing the rejected red part of the sun's rays right at your face.
[4:04] SPEAKER_00: And that bounce light travels straight into your eyes.
[4:08] SPEAKER_00: Once that rejected red light hits your eye, it passes through a little black hole called the pupil.
[4:14] SPEAKER_00: Your pupil expands in the dark to let more light in and shrinks in the sun to protect your eye.
[4:20] SPEAKER_00: Oh, the dark spot right in the middle of your eye.
[4:23] SPEAKER_00: So it's basically a window.
[4:26] SPEAKER_00: Exactly! The light shoots straight through the eyeball to a highly sensitive screen at the very back called the retina.
[4:33] SPEAKER_00: It's only about as thick as a single piece of tissue paper.
[4:37] SPEAKER_00: Wait a second.
[4:38] SPEAKER_00: How does a super thin tissue paper screen know what colour the light is?
[4:43] SPEAKER_00: Because it is absolutely packed with microscopic light-catching cells.
[4:48] SPEAKER_00: You have about 120 million cells, called rods, which are super sensitive, but just see in black, white, and grey.
[4:57] SPEAKER_00: 120 million?
[4:59] SPEAKER_00: That's like the population of a whole massive country packed into the back of my eyeball.
[5:05] SPEAKER_00: And that's not all.
[5:07] SPEAKER_00: You also have about six to seven million cells called cones.
[5:11] SPEAKER_00: These are the ultimate colour catchers.
[5:14] SPEAKER_00: Cones?
[5:15] SPEAKER_00: Do they look like tiny orange traffic cones?
[5:19] SPEAKER_00: They are actually shaped a bit like cones.
[5:22] SPEAKER_00: Human eyes normally have three distinct types of cones: red, green, and blue.
[5:28] SPEAKER_00: But wait, if I only have red, green, and blue cones, how do I see a bright yellow banana or a purple shirt?
[5:35] SPEAKER_00: Your brain does the math.
[5:37] SPEAKER_00: If both your red cones and your green cones fire signals at the exact same time, they send a message down the optic nerve.
[5:45] SPEAKER_00: With the body's fastest nerve sending signals at over 200 miles per hour, your brain receives it in a flash and says, aha! That combination means yellow.
[5:56] SPEAKER_00: That's just like mixing different coloured paints together.
[5:59] SPEAKER_00: But what if some of your cones are broken or missing?
[6:03] SPEAKER_00: That is called colour blindness.
[6:05] SPEAKER_00: In the year 1794, an English scientist named John Dalton published the first scientific paper about it.
[6:13] SPEAKER_00: Because he realised he saw the world totally differently than his own brother.
[6:18] SPEAKER_00: Really?
[6:19] SPEAKER_00: What did the world look like to him?
[6:21] SPEAKER_00: To John Dalton, a beautiful pink flower looked bright blue.
[6:26] SPEAKER_00: Today, scientists know that about 300 million people worldwide have some form of colour blindness, most commonly missing the green or red cones.
[6:37] SPEAKER_00: Wait, if human eyes have three types of colour cones, do animals have them too?
[6:43] SPEAKER_00: Do they see the exact same rainbow?
[6:46] SPEAKER_00: Oh, the animal world is incredibly wild.
[6:49] SPEAKER_00: Let's take dogs.
[6:50] SPEAKER_00: For a long, long time, a massive myth claimed dogs only saw the world in black and white, like a really old movie.
[6:58] SPEAKER_00: Yeah, I've totally heard that.
[7:00] SPEAKER_00: Everyone says that.
[7:02] SPEAKER_00: Is it really true?
[7:03] SPEAKER_00: Nope.
[7:04] SPEAKER_00: Dogs actually have two types of cones.
[7:07] SPEAKER_00: They see the world mostly in vibrant shades of blue and yellow.
[7:11] SPEAKER_00: But red and green just look like dark brownish-grey mush to them.
[7:15] SPEAKER_00: Oh no! So if I throw my dog a bright red toy in the green grass, he's just looking for a grey blob in a field of grey blobs.
[7:25] SPEAKER_00: Exactly! That's why blue toys are actually much better for dogs.
[7:30] SPEAKER_00: But let's look at insects.
[7:32] SPEAKER_00: A tiny bumblebee has three colour cones like us, but their vision shifts toward the invisible.
[7:38] SPEAKER_00: Invisible light?
[7:40] SPEAKER_00: What?
[7:40] SPEAKER_00: Like X-rays or something?
[7:42] SPEAKER_00: Close, they can see ultraviolet light, or UV.
[7:47] SPEAKER_00: UV light waves are too short for human eyes to detect, but bees see them perfectly.
[7:52] SPEAKER_00: But why do bees need to see UV light?
[7:55] SPEAKER_00: Do flowers have glowing invisible ink on them?
[7:58] SPEAKER_00: They literally do! To human eyes, a daisy just looks plain yellow.
[8:03] SPEAKER_00: But to a bee seeing in UV, that same flower has massive, glowing dark bullseyes pointing right to the sweet nectar.
[8:11] SPEAKER_00: That is awesome.
[8:13] SPEAKER_00: It's like a secret invisible treasure map just for bugs.
[8:16] SPEAKER_00: It gets crazier! Hold on tight, because the absolute heavyweight champion of colour vision is a marine crustacean called the Peacock Mantis Shrimp.
[8:26] SPEAKER_00: Ooh, a mantis shrimp.
[8:28] SPEAKER_00: How big is it?
[8:29] SPEAKER_00: And how many colour cones does it have?
[8:32] SPEAKER_00: It's only about four to seven inches long, but it has up to 16 types of colour photoreceptors.
[8:39] SPEAKER_00: And as a terrifying bonus, it has clubs on its arms that smash prey at 50 miles per hour.
[8:46] SPEAKER_00: What?
[8:47] SPEAKER_00: 16 colour cones and it punches as fast as a car drives on the highway.
[8:51] SPEAKER_00: Yes! The strike is so unbelievably fast.
[8:55] SPEAKER_00: It creates bubbles in the water that collapse with a tiny flash of light, heating the water to over 8,000 degrees Fahrenheit for a fraction of a millisecond.
[9:06] SPEAKER_00: That is a literal underwater superhero! But wait! With 16 colour receptors, they must see millions of colours we can't even dream of! Actually, scientists recently discovered something shocking.
[9:20] SPEAKER_00: They don't blend colours like we do.
[9:23] SPEAKER_00: Their brains just recognise raw colours instantly, without doing any complex math, saving brain power so they can strike their prey in a flash.
[9:32] SPEAKER_00: Why is colour so important in nature anyway?
[9:35] SPEAKER_00: Why did eyes evolve to do all this complicated wave catching?
[9:39] SPEAKER_00: It's all about survival.
[9:41] SPEAKER_00: Primates, including early humans, evolved three colour cones so we could easily spot bright red, sugary, ripe fruit against a background of dark green jungle leaves.
[9:52] SPEAKER_00: Oh, so seeing red literally meant you got a sweet snack instead of starving in the forest.
[9:58] SPEAKER_00: Exactly.
[9:59] SPEAKER_00: Colour also warns us of extreme danger.
[10:02] SPEAKER_00: Think of the strawberry poison dart frog in Central America.
[10:06] SPEAKER_00: It's only about an inch long, but it's glowing neon red.
[10:11] SPEAKER_00: It's basically wearing a giant neon sign saying, Do not eat me, I am extremely dangerous.
[10:17] SPEAKER_00: Haha, yes, that's called aposemitism, nature's very own warning label.
[10:23] SPEAKER_00: Before we get to the quiz, here's a mind-blowing fact: the colour pink or magenta.
[10:29] SPEAKER_00: It doesn't actually exist as a single wavelength of light.
[10:33] SPEAKER_00: Wait, what?
[10:34] SPEAKER_00: I have a pink shirt.
[10:36] SPEAKER_00: I'm looking at pink things all the time.
[10:38] SPEAKER_00: In a real rainbow, red is at one end with long waves, and violet is at the totally opposite end with short waves.
[10:46] SPEAKER_00: They never touch in nature.
[10:48] SPEAKER_00: Pink is a made-up colour your brain invents when it sees red and violet light at the exact same time, bridging the gap.
[10:56] SPEAKER_00: My brain is officially broken.
[10:58] SPEAKER_00: It's an absolute colour genius.
[11:00] SPEAKER_00: Alright, Finn, it is finally quiz time.
[11:03] SPEAKER_00: Are you ready to test your colourful memory?
[11:06] SPEAKER_00: Oh, I am so ready.
[11:08] SPEAKER_00: Lay it on me, I'm going to ace this.
[11:10] SPEAKER_00: First question.
[11:12] SPEAKER_00: What is the incredible speed that light travels through space in miles per second?
[11:21] SPEAKER_00: Next one.
[11:22] SPEAKER_00: What was the name of the famous 23-year-old scientist who used a glass prism to make a rainbow in 1666?
[11:34] SPEAKER_00: Question 3.
[11:35] SPEAKER_00: Roughly how many black and white rod cells do you have packed into the retina of your eye?
[11:45] SPEAKER_00: Here's number four.
[11:47] SPEAKER_00: What two main colours do dogs see the world in since they don't see red very well?
[11:56] SPEAKER_00: Last question.
[11:58] SPEAKER_00: Which marine animal has up to 16 types of colour receptors and punches its prey at 50 miles per hour?
[12:09] SPEAKER_00: Great job! Let's see how you did.
[12:12] SPEAKER_00: The first answer is, light travels at 186,282 miles per second.
[12:21] SPEAKER_00: For question 2, the scientist who discovered the spectrum with a prism was Isaac Newton.
[12:27] SPEAKER_00: The third answer is, you have an amazing 120 million rod cells in your eye.
[12:34] SPEAKER_00: For question 4, dogs see the world mostly in shades of blue and yellow.
[12:40] SPEAKER_00: And the final answer is, that terrifying underwater boxer is the Peacock Mantis Shrimp.
[12:48] SPEAKER_00: That episode was wild.
[12:50] SPEAKER_00: I am honestly never going to look at a shiny red apple the exact same way again.
[12:55] SPEAKER_00: Or a mantis shrimp.
[12:57] SPEAKER_00: Please remind me to never ever get into a boxing match with one of those super powered underwater creatures.
[13:04] SPEAKER_00: If you love learning all about the crazy mind-bending world of colour, please leave us a five-star review.
[13:11] SPEAKER_00: It really helps other curious kids find the show so we can all learn together.
[13:15] SPEAKER_00: Yeah! Just scroll down on your podcast app and tap those five stars.
[13:20] SPEAKER_00: It's super fast and easy to do.
[13:22] SPEAKER_00: And don't forget to check out our awesome site, kidopoly.com.
[13:26] SPEAKER_00: We have tons of incredibly fun learning games, cool activities, and amazing resources waiting for you right there.
[13:34] SPEAKER_00: Seriously, go to kidopoly.com.
[13:37] SPEAKER_00: It is the best.
[13:39] SPEAKER_00: Also, do you want your name shouted out on the show?
[13:42] SPEAKER_00: Or just want to tell us your favourite weird science fact?
[13:46] SPEAKER_00: Send us an email at hello at kidopoly.com.
[13:50] SPEAKER_00: We absolutely love hearing from you.
[13:52] SPEAKER_00: Thank you so much for exploring the colourful science of sight with us today.
[13:57] SPEAKER_00: See you next time on Science Is Not Boring.
[14:01] SPEAKER_00: Bye everyone! Watch out for invisible bee treasure maps.

Shows are listed from Apple Podcasts' charts and directory, and Podcast Index where it is used. Every show and episode belongs to its publisher and plays from the publisher's own feed; this site hosts none of them.