Most people assume everyone sees the world the same way. Same sky, same grass, same autumn leaves catching the afternoon light. But for a small number of people — almost exclusively women — the world is something categorically different. Not just richer in shade or contrast, but populated with colours that the rest of us have no name for, no reference point, no way to even imagine. This isn’t a superpower from a comic book. It’s tetrachromacy explained in full biological detail, and it’s stranger and more humbling than most people realise. What Tetrachromacy Explained Actually Means To understand what tetrachromacy is, you first need to understand what the rest of us are working with. Human colour vision is built on photoreceptor cells called cones, concentrated in the central part of the retina. Most people have three types of cones, each tuned to absorb light at different wavelengths — roughly…