This versatile oil contains a blend that naturally protects against certain environmental factors. (essentiallymel.com)
Certain environmental factors such as sun exposure can also make the line darken again. (thetoddle.com)
It is entirely possible (in general logical terms) for object X to exist in state B by default (genetics, programming, design, etc) and to only shift to state A provided certain environmental factors. (nakedpastor.com)