I remembered when it came out it was called "coloured oleo". There was a little button on the inside of the bag, you'd squeeze and mush it up till it was the colour of butter. I was pretty young then so it's a little vague. My father had a great tutorial on the margarine industry and sadly he didn't record it, just like his war stories.
I remember, as a kid, signs on the side of the road where to go in MN to buy it because it was illegal to sell it in IA.
Now they grow corn for ethanol. Go figure.
Is everything better with Blue Bonnet on it?