Hi

In Odoo 11, the default color for the .text-danger class in Bootstrap is not white (#ffffff). It is typically a dark red color (#dc3545) that indicates an error or danger state.

If you are seeing the text in white color for the .text-danger class or .has-error class, it is possible that there might be some custom CSS or theme modifications affecting the default Bootstrap styles.
Here are a few steps:
-> Check for custom CSS: Look for any custom CSS files or code that might be overriding the default Bootstrap styles. Inspect the HTML elements using the browser's developer tools and check the applied CSS rules to identify any conflicting styles.
-> Check for theme modifications: If you are using a custom theme, review the theme files and settings to ensure that the Bootstrap styles have not been modified unintentionally. Check for any color-related modifications that might be affecting the .text-danger class or .has-error class.

Hope it helps