Is it possible to add metadata to each product tag?
Example: https://xyz.com/collections/roses/color-pink will I be able to add unique metadata to the tag pages?
You could do that!
One approach would be to store the metadata in a collection metafield. In the theme code you grab the tag, see if there’s a matching metafield, and show it. I realise that is super high level and doesn’t tell you the code but not sure how much code skills you have so assuming lots (for now).