How good is YOUR colour perception? Deceptively difficult test tasks you with finding the boundary between two shades – so, how far can you get?
How good is YOUR colour perception? Deceptively difficult test tasks you with finding the boundary between two shades – so, how far can you get?
The Challenge of Color Perception
A new interactive test invites participants to reevaluate their grasp of color perception. It presents pairs of hues and challenges users to identify the dividing line between them.
Initially, the task seems simple, but the difficulty escalates rapidly. As the game progresses, the colors grow increasingly similar, making the distinction harder to spot.
‘You see two colours. Click on the line between them. That’s it. It starts easy. It does not stay easy,’ the game’s instructions state.
The objective is to determine your Just Noticeable Difference (JND)—the smallest perceptible shift in color that your eyes can detect. The test typically spans 40 rounds, with an average score of 0.02.
How the Test Works
To play, visit the game and tap the ‘Let’s go’ button. Each round displays two color blocks, requiring you to pinpoint the boundary between them.
After each attempt, you receive feedback on your accuracy. Early stages feature stark color contrasts, such as grey and blue or brown and orange. However, as the game advances, the shades converge, testing even the most discerning eyes.
At the conclusion, you’re provided with a score and a comparison to others who have completed the test. A low score might prompt a message like: ‘Rough. But look, I once failed a colour vision test because the room had fluorescent lighting. Environment matters. Try again in a dark room with your brightness cranked. Or don’t. I’m not your mum.’
Behind the Science
The test was crafted by software engineer Keith Cirkel to investigate the precision needed for color recognition on digital screens. His aim: to uncover the threshold where human vision can no longer distinguish subtle differences.
Color perception relies on photoreceptors in the eye, specifically cones, which detect different wavelengths of light. Humans and many animals possess three types of cones, enabling a spectrum of color vision from red to blue. Some species, including many birds, have four cones—a trait known as tetrachromacy—which allows them to perceive ultraviolet light.
When light triggers these photoreceptors, electrical signals are sent to the brain via the optic nerve. These signals merge at the optic chiasm, where the brain compares the two visual inputs to create a cohesive image.
Hard Mode and Player Reactions
For those who conquer the standard test, a Hard Mode variant awaits. This version features nine squares—eight of the same color and one differing slightly. The goal is to locate the odd square out.
Players have shared their experiences online. One noted, ‘This is great fun. How good is your colour perception? What are the finest shades you can distinguish? Apparently I’m a bit special.’ Another remarked, ‘Some were just completely uniform to me. I had no idea. Had to keep tilting my screen all ways to try to spot a border but still ended up guessing.’ A third joked, ‘Not bad considering I’m colourblind.’
