Shopify custom coding

I am looking for a skilled Shopify developer who can help with some custom coding on my Shopify website.

The task at hand involves some modifications to the product option buttons on my site. Specifically, I need one of these buttons to stand out from the rest, having a different color. This is to be used to highlight a product as a "Best Seller", "Best Gift", etc. I'd like a tag or label on this button with the corresponding text.

Here are the requirements in detail:

Change the color of a specific product option button to make it stand out from the others.
This button must be able to display a custom tag (such as "Best Seller", "Best Gift", etc.).
The solution should be flexible enough so that I can easily update which product has this special tag and the text of the tag.
The changes must be compatible with my existing site theme and design, without causing any layout or responsiveness issues.
The code should be clean, maintainable, and well-documented so future modifications can be made easily.
If you could provide examples of similar work you have done in the past, that would be appreciated.

(attached you can find an example)!