Which setting should you prioritize to give merchants control over theme design changes?

Prioritizing schema settings is essential for giving merchants control over theme design changes because they allow for customizable options within the Shopify theme editor. By implementing schema settings, you enable merchants to modify various aspects of their theme directly from the Shopify admin interface without needing technical skills or direct access to the code. This enhances flexibility and empowers merchants to tailor their store's appearance and functionality to better fit their brand and meet business needs.

Schema settings allow developers to define user-friendly fields—like text boxes, color pickers, and image selectors—in the theme's code. When these settings are arranged properly, they create an intuitive interface for merchants, making it easy for them to experiment with different designs or adapt the theme as their needs evolve.

In contrast, hard coding all values within theme files restricts flexibility, as it ties design elements directly to the codebase and would require a developer to make any changes. Using external CSS files can help with organization and maintenance but doesn't inherently provide merchants with control over design changes within Shopify's interface. Providing a default theme style only offers limited customization options and does not empower merchants to adjust their themes as they see fit.