Every cat owner has watched their pet sprint wildly after a toy, only to lose track of it when it stops sliding across a rug. The explanation lies in chromatic contrast.
Drop a bright red plush mouse onto a green living room carpet. A human spots it instantly because the human red and green photoreceptors produce severe chromatic contrast. To a cat, the red plush reflects light that registers as dull gray, while the green carpet also registers as a muted, desaturated yellow-gray. The object's chromatic contrast plummets to near zero. If the toy stops moving, the cat's motion-detecting visual circuits stop firing. The toy effectively disappears against the background.
Swap that toy for a royal blue or violet object, and the scene changes dramatically. Cats possess dense populations of short-wavelength cones. A royal blue mouse stands out with sharp luminance and chromatic distinction against wooden floors, tan tiles, or green rugs, allowing the feline visual cortex to lock on even when the object is stationary.
