Hi dr.kappl,
Thanks for reaching to us.
1. Please navigate to Theme Settings > Page Title. You can change background color for all pages. https://prnt.sc/3FjyvI7dqUyw
2. In case you want to do it for specific conditions, you can use Theme Presets https://prnt.sc/j4tzqilwAMAn Then navigate to Theme Settings > Page Title and change background color, which working for Product Categories post type only.
Please refer to our documentation https://xtemos.com/docs-topic/theme-settings-presets/
Happy New Year
Regards,