Pick the exact color swatch under time pressure to test your visual accuracy.
When this game asks you to find the "different" square, it doesn't just pick two random colors out of a hat. It mathematically calculates a color that is exactly a certain "distance" away from the base color in the RGB color space.
In digital screens, a color is represented as an array of three numbers from 0 to 255. For example, pure red is [255, 0, 0].
To create the "odd one out", the game applies a Delta (Δ) to these values.
At Level 1, the delta might be 30. So if the base color is [100, 100, 100] (gray), the odd color might be generated as [130, 130, 130] (a lighter gray). As your score increases, the delta shrinks.
By Level 20, the difference between the base color and the odd color might only be 3 points on the RGB scale. However, this reveals a massive flaw in the RGB color space: it is not perceptually uniform.
Because human eyes are highly sensitive to green light but poor at distinguishing blues, a delta of 5 in the green channel is obvious to the human eye, while a delta of 5 in the blue channel is nearly imperceptible.
This is why professional designers use advanced color spaces like CIELAB or OKLCH to generate palettes, as they mathematically map to how humans actually perceive color rather than how screens emit light.
Why is the RGB color space considered 'perceptually non-uniform'?
