Yes, you can switch back to default page at any instant by using the Canvas Assignment.
When you design a new record detail page using Canvas, you will be offered an option to assign the new page to the desired profiles. For each profile you can select which view is applicable — whether the Standard (Default) View or the new user created canvas view.
The Canvas you created will be activated only for the profiles you have selected here. You can always deactivate the view at any point and revert to the Standard View of the record detail page if you so wish.
To access Canvas Assignment:
1. In your Zoho CRM account, go to Setup.
2. Under Customization, click Canvas Builder.
3. In the Canvas page, click the Canvas Assignment button.
Alternatively you can access Canvas Assignment, while working inside a Canvas builder.