Recent construction trends include the use of aluminum, plastics, metal, glass backing and even ceramics. Each material used has unique properties that are both advantageous and complimentary to the device but often come with limitations.
As with the fashion world, every new season (or phone launch) introduces new or elaborately names colors. Kind of Blue anyone? With the color being influenced in its final appearance by those materials chosen.
For example, a glass body allows radio waves to pass through and better facilitates wireless charging, but unless utilized properly, could make the phone more fragile.
In order to make the display as resilient as possible, many manufactures use Corning Gorilla Glass.
A devices ability to withstand dust and moisture is identified via a IP Rating.