Or maybe they were red.....I forget alot lately........
And before the red cells? Drum roll, please... remember the gold, red and white cells? At least the 9 volts were, 35 years ago. I still have a gold, red and white 9 volt sealed in it's clear cellophane wrapper. "Iron clad!" And they said, "New Formula" for years! Every now and then a prick my DVM probes through the cellophane to make sure it still has 9 volts. Yup, sure 'nuff, ready for the next power outage!
About those free battery of the month cards. I was naughty. Our Rat Shack's did not punch the cards, but rather checkd the month off with a ball point pen. As a crafty kid (as opposed to the crafty adult I became) I ran a strip of scotch tape across the months. When they penned the card, I just erased it off the scotch tape and went to the next store, or went back a few days later. Seems like a lot of trouble, but the batteries were like gold to a kid with no allowance, and one cell a month just wasn't going to cut it!