Robert Copeland has documented eight distinct versions of blue produced by the Spode factory, but variations often occurred.  Early designs were printed in a very dark blue.  As knowledge of the use of cobalt evolved, the factory produced wares in different hues--from midnight blue to versions with more red, such as royal blue, to mandarin, and some in lighter shades--all in an effort to respond to their customers preferences.


Willow 2
Worcester Wheel
Zeus in His Chariot