How can I show product swatches on my category page?

There is an option for swatch visibility on Category Pages.

Pearl Theme > Theme Options > Category Page > Swatch Options

• Display Swatches: display swatches on products from category page [ No / Yes / On Hover ]

Make sure swatch visibility is set to 'Yes' or 'On Hover' if you need swatches to be visible on Category pages.

Other swatch options available that may help

Pearl Theme > Theme Options > Category Page > Swatch Options:

• Display Swatch Tooltip: display swatch tooltip when hovering over swatches on products from category page [ Yes / No ]

Weltpixel -> Category Page ->Item Swatch Options:

• Radius: set radius for swatches on items in category pages [ in px ]
• Width: set width for swatches on items in category pages [ in px ]
• Height: set height for swatches on items in category pages [ in px ]
• Font Size: set font size for swatches on items in category pages [ in px ]
• Swatch Align: set swatch align on items in category pages [ left / center ]

In case changes are not applied to the storefront please refer to the article below which explains the most common problems for admin options not visible in storefront.

If swatches still do not apply to your Category Page products, check if they show up on Product Pages. If you can't see swatches on Product Pages, the problem is most probably related to product configuration or Magento swatches not being setup correctly.  

The Pearl Theme uses default Magento 2 swatch configuration. In our Pearl Demo (pearl.weltpixel.com) we are using default Magento 2 sample data for product and swatch configurations. 

Please check the 'Swatches' section in Chapter 12 of the official Magento 2 documentation. This should offer good guidance on how to create Swatches in order to show up on your Product Pages and Category pages.

Official documentation below:

https://docs.magento.com/m2/ce/user_guide/catalog/swatches.html  

https://docs.magento.com/m2/ce/user_guide/catalog/product-types.html