I Googled a bit, but I must have not been using the correct terms because the search results were not helping me.
However, I was finally able to figure out my issue. I still don't quite understand why I have to go through Terminal (mainly because I really don't know what Terminal does - insert embarrassed emoji), but I followed the directions and saw that the printing preference was still in color.
See here from Coupons.com (also pasted below).
How do I change the print mode of my printer on Macintosh?
Our Coupon Printer uses the default settings set in your printer software. You must make any changes there to affect what tray is used for printing, whether you print in color or grayscale, etc.
In order to have such applications adhere to your default settings, you have to interact with the underlying printing system CUPS. Please follow these steps: