Gray lenses are the most popular choice for sunglasses because they don't change the color of what you're looking at. They offer true-to-life color perception, so everything looks as it should. They're also great for reducing glare and bright sunlight, making them a good choice for outdoor activities like driving, fishing, and boating. Black lenses are similar to gray.
Bamboo has a distinctive aroma when cut or sanded but it otherwise doesn't have a strong scent. You will probably be able to smell the inside of your bamboo case as it has not been sanded or polished. It has a distinct earthy scent, simply because, it is of the earth.