Movie S2.

Cuttlefish Sepia latimanus showing chromatic signaling to conspecifics. This movie shows how some shallow water tropical cuttlefish break camouflage while signaling to conspecifics in contrast to the same species in camouflage in Fig. S1 A–D. Although they could easily produce the same luminance function in black and white with less chromatic contrast, which is done in many other Sepia species, some shallow water cuttlefish and squid signal to each other with highly chromatic displays that are conspicuous for their predators with color vision. The chromatic signal is interspersed with black lines, allowing for a determination of chromatically induced defocus. The colorful mantle signals in the leftmost animal at 30 s show bright gold and purple separated by a black line, allowing the sign of chromatic defocus to be resolved for each color (whereas if the two colors were directly adjacent, this determination would be impossible). Note that this movie was filmed in the natural light environment of these organisms without any artificial lights or filters. This movie shows that, in the natural lighting environment, these signals appear “colorful” to vertebrate predators with color vision through multiple photoreceptor channels. Additional examples of chromatic signaling to conspecifics are shown in Fig. 1 and Fig. S2. Movie courtesy of Jaime Aguilera.