The Color of Distance Series by Amy Thomson

Juna is the sole survivor of a team of surveyors marooned in the dense and isolated Tendu rain forest, an uninhabitable world for humans. Her only hope for survival is total transformation--and terrifying assimilation--into the amphibian Tendu species. Juna will learn more about her own human nature than ever before.

Bound to the human race by a lifesaving link and a sacred pledge of honor, two members of the alien Tendu species leave the safety of their homeland and board a spacecraft headed toward Earth. Isolated from humans because of their alien bodies, customs, and language, the Tendu must learn the ways of Earth in order to survive... moreBound to the human race by a lifesaving link and a sacred pledge of honor, two members of the alien Tendu species leave the safety of their homeland and board a spacecraft headed toward Earth. Isolated from humans because of their alien bodies, customs, and language, the Tendu must learn the ways of Earth in order to survive. But if their attempts at human convention are not enough to overcome the suspicions they have aroused, their voyage to Earth could cause more than a gap between the two worlds - it could bring about their ultimate downfall... less