Understanding how selection jointly acts on multiple traits is challenging yet fundamental to decipher the evolution of complex phenotypes. While Morpho butterflies are famous for the blue iridescence of some species, it presents a very high diversity of wing morphologies, including wing coloration. While the evolutionary drivers of iridescence remain elusive, we suggest that predation plays a major role. During flight, iridescence indeed produces bright flashes that might confuse predators and enhance erratic escape. This effect should thus favour the coevolution of colour and escape flight performance, and we thus predict their joint divergence across the Morpho genus. To test this hypothesis, we characterized escape flight in Morpho butterflies from 16 species, presenting contrasted colorations. We used stereoscopic videography in the wild to record the escape flight of Morphos in their natural habitat and reconstructed their 3D flight trajectories using a deep-learning approach. We elicited escape flights using standardized insect net swings and compared flight kinematics before and after the attack. Iridescence was characterized using a spectrogoniometer. The comparative analysis of escape flight kinematics across species is ongoing aiming at identifying the evolutionary relationships between flight and colour - these analyses will be presented. Results on Morpho menelaus, a large blue iridescent species, show a sharp increase in erraticity associated with a decrease in speed following the attack, suggesting a biomechanical trade-off between speed and manoeuvrability. Such an erratic flight is expected for a bright blue species, as it might favour escape by increasing the production of confusing blue flashes.