Hi,

To change the font color of your "Out of Stock" message in Odoo, you can use the below methods. First, use the Website Editor by enabling Edit Mode, clicking on the message, and changing the font color through the style options.

for example:

If customization is needed at the template level, activate Developer Mode, go to Settings > Technical > User Interface > Views, locate the template rendering the message, and directly add a style tag like <div style="color: red;">Out of Stock</div>. Save the changes and refresh the website to apply.

for example:

Hope it helps