Green’s Dictionary of Slang

Californian n.

[the association of the red, i.e. gold colour, with the Californian Gold Rush]

a dried red herring.

Cassell’s Mag. Jan. 245: Very large quantities of cured herrings came from the Firth of Forth, they were more cured, dryer and salter than those from Norfolk. Some were sent very dry indeed, as hard as a stick, and of a very deep red colour; such were used, as similar fish now are, for exportation. About the time of the gold discoveries, some one applied the term Californian to these [...] and Californians such highly-coloured herrings are called to this day [F&H].