Hello,

It is not enough just to set a product as a variable. You need to add attributes and then create variations.

Please read and follow the instructions: https://docs.woocommerce.com/document/variable-product/

As soon as you create variation, configure the swatches https://xtemos.com/docs/woodmart/variable-products-swatches/

Then you will go to Appearance > Widgets and add WOODMART WooCommerce Layered Nav to the Shop page widget area.

Best REgards