Frogleg said:

I've read that wartime (WWI) oleo
came with dye pellets to knead in to make the (presumably white) fat
look more like butter.

Not just during wartime. I remember being regularly given the kneading job
around 1952 or so. I would have been 7-8 years old at the time. The undied
margerine was ghastly white and looked (and tasted) like Crisco. (I remember
trying that too.)

--
Bob
Kanyak's Doghouse
http://kanyak.com