This color change caused by formation/dissociation of the complex is due to the bathochromic effect (a change in the
wavelength absorbed by compounds). Free astaxanthin absorbs light at 470-472 nm (yellow, orange and red) and with the formation of the astaxanthin-protein complex, absorption at 632 nm (green, blue or purple) is observed (WEESIE et
al., 1995; CIANCI et al., 2002).