Question Dynamicly change a background sprite of a custom VisualElement

I am doing a toggle button with an icon inside. I am using the Basefield<bool> to inherit my class to benefit of the RegisterValueChangedCallback.

The only problem is, I would like to use this new toggle and change the sprite of the background but as it is a VisualElement of custom control, everything is gray and cannot be changed.

Do I need to use a class of is there an other way?

 

Thank you for your answer.

It would be easier to access to the VisualElement even for other application like changing the structure of an visualElement already existing to apply fancy uss of modifications.

For now I am using the uss to change the background image without using code since it can be such a pain to reference the guid of the sprite or make a database or something else.