Research overview: the blue-yellow axis of feline color perception

Dichromatic animals typically perceive color along a single axis, and in cats that axis runs roughly from blue to yellow. This overview surveys evidence that cats discriminate short-wavelength from longer-wavelength light while confusing colors that differ mainly along the red-green dimension humans see. The blue-yellow organization follows directly from the cat having two cone types with separated spectral peaks. The survey discusses how this shapes a cat's likely visual experience, with reds and greens appearing comparatively muted or similar, and blues and yellows providing the main chromatic contrasts. For caretakers, this has been used to suggest that toys in blue and yellow may be more visually distinct to cats than red ones, though motion remains the dominant cue. Characterizing the blue-yellow axis turns abstract dichromacy into a concrete picture of how cats may experience color.