The CSP app by TechiePugs lets you to add color/pattern for showing variant swatches on collection page. You can choose from a variety of themes.
We also have added functionality for showing the swatch button on product page. This add on will be free for first 20 customers.
Install the App now and get a 7 days trial period free of cost. You can checkout a live demo of the CSP app :
Note that this is a demo store for the CSP app. You can try the app on your store for free and see if it fits your needs.