Change Category default Background

Hi, I am trying to change the default background of a category titles.

I have imported Base dummy content.
Previously I could set a default color for product categories and pages.

But now a default image appears in all product categories. This is something that I cannot change.

I can change the backgrounds of the page titles from the menu settings. I can set a default color or background image. But I can’t do this with categories.

In the categories I can only set an image by accessing “Products”> “Category”> “Image for category heading
“, but what I need is to set a default color for all categories, not an image.

How can I set a default color? How can I remove this default image?

Thank you.