While permanent color is just that â permanent â it does tend to eventually fade with time. Hello, oxymoron. However, it's the only type product that can actually lift pre-existing color out of the hair, since it relies on hydrogen peroxide and ammonia to get the job done. It's also the only type of hair color that can cover gray completely, and it also has the ability to change the hair up to four levels â sometimes even five. After combining the tint of choice with a developer, the permanent hair dye is applied, and the ammonia immediately begins opening up the cuticle. Then, the peroxide moves in, breaking up the melanin in your hair shaft, replacing what's left with the pigment of your choice (hopefully).
tropical zone. n the part of the Earth's surface between the Tropic of Cancer and the Tropic of Capricorn; characterized by a hot climate. any of the geographical zones loosely divided according to prevailing climate and latitude.
effect of climate on landform evolution. in valley: Tropical zone. Tropical regions are dominated by dense vegetative cover and deep weathering profiles. In continuously humid tropical zones, fluvial activity is facilitated by intense rainfall but inhibited by the protective effect of rainforests. The lateritic soils of these regions, however, do not promote deepâ¦ Read More; horticulture. In horticulture: Tropical zones. There is no sharp line of demarcation between the tropics and the subtropics. Just as many tropical plants can be cultivated in the subtropics, so also many subtropical and even temperate plants can be grown satisfactorily in the tropics. Elevation is a determiningâ¦ Read More; marine productivity