Removing themes
You can remove a theme from your online store within the Themes page in your Shopify admin.
You can add up to 20 themes to your online store. If you already have 20 themes, then you can remove themes to make room for more.
On this page
Remove an unpublished theme
You can remove an unpublished theme from your admin. This is a permanent action.
Steps:
Remove your published theme
If you want to remove the theme that you currently have published, then you need to publish another theme first. After you publish another theme, you can remove the unwanted theme from your store.