Definition of Littler's blue in English:
Littler's blue
noun ˌlɪtləz ˈbluːˌlɪt(ə)ləz ˈbluː
A rich blue colour applied to porcelain or stoneware.
Origin
Early 20th century; earliest use found in The Burlington Magazine. From the genitive of the name of William Littler, English pottery manufacturer + blue.