Chemist here - thus a probably stupid physics related question. I will spare you the details and the background and try to break it down: (Assumably) I am looking at a system of lamellar micelles that have a somewhat defined mean interlamellar distance. These can reflect light and at a certain angle the bragg equation can be satisfied so that constructive interference can occurr. So let's say we look at two light waves that got scattered and can interfere constructively, does that increase the ''visibility'' of that wavelength for the human eye? Or to rephrase: I am looking at white light compared to originally white light in which the 500 nm wavelength did interfere constructively, will that second ''white'' light look like 500nm light, so lets say blueish green? A little background: If I shine white light on the observed substance I will observe green light from an angle that is close to the light source - thus green light has to be able to interfere with the micelles and get reflected into my eyes. However, every way that physically reflects light back to my eyes can not be that wavelength-specific, so that all other wavelengths despite the observed wavelength could be cancelled out or not reflected back into my eyes. Consequently, the explanation given above that is supposed to describe the iridescence is only viable if the constructive interference increases the ''intensity'' of that specific wavelength and makes me see that wavelength, even though all other wavelengths get reflected into my eyes as well. Just to clarify: From what I have read Fresnel and Snellius-Equations state that the amount of light that will transmit or get reflected is indeed wavelength-dependant, however it seems impossible that you could find circumstances in which a very small range of wavelengths would get reflected while ALL other wavelengths in the mix would not get reflected at all. Consequently all wavelengths will get reflected back to my eyes, some more and some less but I doubt that this could explain the visibility of colour. Thanks in advance for your answers!