When I was a kid, you bought oleomargerine as a white brick or in a bag. The coloring agent was separate. You had to add it and mix it well to all of it was yellow. This took a lot of time. It was our job to do this as it was very time consuming. I swore that when I grew up, I would only buy butter. I have kept that promise to myself.
Margerine at that time was made from lard. Now it is chemicals and oil products. Read the labels. When you use it for baking cookies, the oil spreads and your cookies do not puff up like they do with butter. Butter has natural water in it and when in a baked product, it causes the water to change to steam thus a higher product. Do not exchange butter for margerine. But please do exchange margerine for butter. You will have a better product and it will taste so much better. If a recipe calls for margerine, it is probably a very old recipe or the person who wrote it cannot or will not go to the expense of purchasing the better product of butter. Butter is