WooCommerce Variation Swatches is the most popular attribute variation plugin in the WordPress plugin catalog.

Demo:

WooCommerce Variation Swatches Pro is a simple plugin, but it does a great job. Turns the drop-down list of product attributes into beautiful samples. This means that you can turn a drop-down list of product choices into swatches of colors, buttons, radios, and images.

Consequently, the plugin significantly expands the possibilities of variations. Users do not need to open the drop-down selection box and see which options are available for a variable product. Without pressing extra clicks and without spending extra time, they can quickly select the desired option.