Colour is what our eyes see when light shines on things and bounces back to us. It is a part of light, more exactly, the part of light that we can see.
Light travels in waves, and each color we see is caused by light waves of a different length. For example:
- Red light has longer waves.
- Blue light has shorter waves.
- All the colours we see, such as green, yellow, orange, and purple, are made up of waves of different lengths.
So, colour is not really inside the object itself, it’s how light interacts with the object and how our eyes and brain understand that light.
How we see colour
- Light source:
Everything starts with a source of light like the Sun, a lamp, or any other bright object that gives off light. - Light hits an object:
When light shines on something, part of that light is absorbed by the object, and the rest is reflected.- A red apple absorbs all the other colours of light but reflects red.
- A white shirt reflects all colours of light.
- A black coat absorbs almost all the light and reflects very little, which is why it looks dark.
- Light enters the eyes:
The reflected light travels to our eyes. Inside the eyes, on the back part called the retina, there are special cells called cones and rods.- Cone cells help us see colours. There are three types: one for red, one for green, and one for blue light.
- Rod cells help us see in dim light or at night, but they don’t detect color well.
- The brain interprets the signal:
The cone cells send electrical messages through the optic nerve to the brain.
The brain mixes these signals and tells us what color we are seeing red, blue, yellow, pink, etc.
Fact: When we mix all colours of light together, we get white light. But when we mix all paint colours together, we get black or brown because paint colours mix by subtracting light, not adding it. That’s why colour on a computer screen (light) works differently from colour on paper (ink or paint).
DOES AN OBJECT REALLY HAVE COLOR? Not exactly! The object itself doesn’t have colour the way we see it. What happens is: The object’s surface decides which colours of light to reflect and which to absorb. Our eyes and brain then turn that reflected light into what we see as colour. So if you say “the apple is red, ”what’s really true is the apple’s surface reflects red light and absorbs all the others. Your eyes pick up that reflected red light, and your brain says, “That’s red!” Example: If you shine blue light on the same red apple, it may look black or dark, because there’s no red light for it to reflect. This shows the apple isn’t always red it looks red only when red light is present. In short: colour doesn’t live in the object, it lives in the light and in how our eyes and brain understand that light.In Simple Words : Color happens when light reflects off objects and reaches our eyes. Our eyes and brain work together to turn that light into the colorful world we see every day.
STORY: THE COLOR-CHANGING BALL
One day, a boy named Arun had a bright red ball. He loved how shiny and colourful it looked in the sunlight. But that evening, he took the same red ball into his room and turned on a blue light. To his surprise, the ball didn’t look red anymore! It looked dark brown or almost black. Arun was confused. “How did my red ball change colour?” he asked his mom. His mom smiled and said, “It didn’t really change colour, Arun. The ball isn’t truly red; it just reflects red light. In the sunlight, there’s lot of red light, so your eyes see it as red. But under blue light, there’s no red light for it to reflect so it looks dark!” That’s when Arun understood colour depends on light, not just the object. If the light changes, the colour we see changes too.
Moral of the story: The red ball is not always red. It looks red only when red light is shining on it. So, colour is not really inside things; it’s a mix of light, reflection, and our perception.
