When we’re kids, in school, we’re taught that the primary colours are red, yellow and blue. But this isn’t entirely accurate when it comes to light. Pure white sunlight is made up of a whole spectrum of colours, with the primaries actually being red, green and blue. Our cameras with Bayer filter arrays on the sensor see RGB. Our monitors also display RGB.
But have you ever wondered how we’re able to get so many different colours from just three? And why just blasting red, green and blue LEDs at an object doesn’t always give you true white light? This fascinating video from Technology Connections isn’t really specific to photography, but light in general, and how red, green and blue affects our (and our camera’s) perception of colour.