Cuttlefish Camouflage Lab (2D)

Reef

Reef patchiness 18

Chromatophores

Reaction speed 55

Swim speed 30

Actions

Live Readout

Camouflage match

—%

Adapting for

0.0s

Chromatophore activation 0%

Reef sample

Skin colour

How it works

Real cuttlefish skin carries stacked sacs of pigment — chromatophores — each pulled open or closed by tiny muscles under neural control, layered over a light-scattering iridophore base. This lab models three pigment channels (yellow, red-brown, black) as expansion values between 0 and 1 sitting over that pale base.

Each frame the reef colour directly under the cuttlefish is sampled from a procedurally generated sand/coral/rock/kelp reef (built from a coarse random grid, smoothed by bilinear interpolation so patches blend naturally). A gradient-descent controller compares the current skin colour to that target and nudges each pigment's expansion along the direction that reduces the mismatch, scaled by the reaction-speed slider — a simplified stand-in for the cuttlefish's real closed-loop visual feedback system.

Match quality is scored with the redmean formula, a low-cost approximation of perceptual colour difference (it weights the blue channel by how bright red already is, which tracks human colour perception far better than a flat RGB distance). Crossing a patch boundary resets the "adapting for" timer so you can watch how reaction speed and swim speed trade off against how quickly the mismatch closes.

Higher reaction speed closes the colour gap faster · higher swim speed crosses patches sooner, forcing the controller to keep re-adapting.