Vivitar Cromo Blend filters?

[railwayman3]

Just come across some of these filters on Ebay.

Does anyone know anything about them, or their purpose and the effects produced, please?

I've tried Googling, but not found anything particularly useful.

 

[Russ - SVP]

They're equivalent to todays, bi-color polarizers. <Made for color. Kinda gimmicky...

KK