>>2229816But different colours (tint) afect how they reflect light, so I dont know why you say they are different.
Also there are many gray outer layer sunglasses and when you receive them at home and take a look, there is a yellowish tint in the inside layer, so if you expected a dark sunglasses to protect you from the sun is counteracted with the yellow layer.
Or why there are some cyclists sunglasses that are all colours in the outlier layers? What sense does this make? For what purpose?