People in Japan think it's good to have white skin.
Japanese people think being fair skinned is a good thing.
この場合、次のような言い方ができます。
ーPeople in Japan think it's good to have white skin.
「日本では肌が白いことが良いとされています」
ーJapanese people think being fair skinned is a good thing.
「日本人は色白が良いと思っている」
fair skinned で「色白な・肌が白い」
ご参考まで!