Hello, Eduardo.

1. You may decide if to use the color filter by tags in the Sidebar.

Please read more details in our user manual -

https://mpithemes.gitbook.io/shella-shopify-theme/collections/sidebar/filters

Or filter by product variants -

https://mpithemes.gitbook.io/shella-shopify-theme/collections/sidebar/option-filters

2. If you need to add custom colors (in different language or unique color names) as product swatches or in the sidebar section, you can configure them in “Product variants” section.

You may need to tick the option "Enable 'Product variants' global section for fine-tuning options" at the Theme settings -> Product -> Variants to add custom colors -

https://prnt.sc/v381za

Then, you may need to navigate to Sections -> Product variants to configure custom colors -

https://prnt.sc/1upqnyy

How to configure Product variants you may find in our user manual.

Please, read more information here -

Please note, you may need to add the same color name both in Shella Editor and color variant for a product at Shopify admin.