How to highlight a new color for an existing product?

Hello,
I’m trying to promote one color on existing product.

Actually, many of our products (clothes) are not new in themselves but we propose a new color which is.
In order to highlight/promote only this new color, and not the others of the same product (notably to include it in the ‘New’ collection which works with a tag system on product):
do we have to create a new product with this color? or is there another method?
There are many products in this case and creating new product files creates duplicates which can be confusing, hence our question.

Thank you in advance for your help