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.
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.