https://online2.tingclass.net/lesson/shi0529/10000/10183/624.mp3
https://image.tingclass.net/statics/js/2012
They also put cuttlefish in tanks with a range of different checkerboard patterns to see how well they could differentiate between different colors or brightness. When in front of a high-contrast background, like alternating dark and light squares, the cuttlefish skillfully mimicked the checkered pattern. They also tried checkerboards of different colors that were very similar in brightness. That is, colors that would look the same shade of grey in a black and white photo. In front of these low-contrast checkerboards, the cuttlefish just turned a single solid color. So it seems that cuttlefish camouflage themselves by matching light intensities of objects rather than their colors. But how they match colors so accurately is still a mystery.