A new eggshell color mutant was discovered in the Japanese quail. This trait was named "celadon" and was shown to be controlled by an autosomal recessive gene. Therefore, the gene symbol ce was proposed. This gene and an autosomal recessive gene we controlling a white eggshell trait were shown to be nonallelic. Also, ce was shown to be hypostatic to we. A spectrophotometric analysis revealed that the celadon eggshell pigments are protoporphyrin and biliverdin as in the wild-type eggshell, but the protoporphyrin content is much lower than that of the wild type. The biliverdin content was 44% of the wild type.