Custom attribute not showing on variable products

I have created a “color” attribute for all products.
In Field Mapping, I set it to the Google Merchant color attribute and everything is working.

However, in variable products, everything that is mapped from product attributes is not displayed.
PS. This attribute is NOT used for variables, as it only serves to better organize the items.

How can I propagate the attribute of the parent product, so that the corresponding field is created in the variable product?