How can I highlight sale items in my collections for Black Friday?

I’m not sure the title is clear, but I am creating my Black Friday sales. I have several categories of sale items planned (% discounts & “Buy 2, Get 1 Free”).

I am working on grouping the items into their relevant collections. That is no problem. I have previously linked the collections from my homepage, so I assume that will be no problem.

However, what I would like to do is have the items themselves be tagged/marked/highlighted wherever they appear.

Example: Should the customer click on the category “hats,” they could see the full selection of hats but the individual hats that are a part of the “Buy 2, Get 1 Free” sale would be relevantly marked. Is this possible or is it theme dependent? If it’s relevant, I’m using the Debut theme.

Possibly worth noting: As this is primarily for sale-specific collections, I intend for this to be temporary as the collections will be removed at the conclusion of the sale.

Thanks for any help or advice!

Does anyone have any thoughts on doing this? It seems like it should be straight-forward, so I hope I’m just missing something right in front of my face.

Thanks!