FacetWP can be integrated with several WooCommerce Plugins:

Variation Swatches for WooCommerce

Variation Swatches for WooCommerce by Emran Ahmed lets you attach colors or images to your WooCommerce product attributes.

With this plugin activated, you can use our Color add-on facet type to filter products by color.

When adding a color facet, set its Data Source to the product attribute containing your custom color / image swatch.

WooCommerce Attribute Swatches

WooCommerce Attribute Swatches by IconicWP, a premium plugin that works similarly to Variation Swatches for WooCommerce (same setup instructions as above).

See also