The center of the white glaze plate in the official kiln is yellow.

A: It is normal that the center of the white glaze plate in the official kiln turns yellow or the blue and white glaze turns black, which is a special process of making porcelain in the official kiln. Official kilns were common in Hongwu period of Ming dynasty, and official kiln porcelain appeared from time to time in the middle and late Ming dynasty. For example, in the Ming Dynasty, the blue-and-white flower cave stone pot in Chongzhen was 12.6Cm high, 5.9Cm in diameter and 7. 1Cm in foot diameter. The pot body is yellow, white, glazed, black and blue, and the picture is like a lovely ink painting.