Celadon is a lovely muted shade of pale green which became famous as a porcelain glaze long ago in ancient dynastic China. Although the technique for making the glaze was invented during the Tang dynasty, the zenith of celadon porcelain making was attained during the Sung dynasty when so many of the aesthetic conventions of Chinese culture came into flower.
The perfect serenity of well-made celadon vessels has been compared to Buddhist enlightenment. Additionally, according to ancient folklore, celadon serviceware and drinking vessels would change color in the presence of poison. Sadly this latter fact is an outright myth, however if the lie resulted in more celadon being produced then perhaps it was worth a few surprised dead Chinese nobles. Celadon porcelain is magnificent.