Hi @Liran Pingle,
I'm sorry there's no OOTB to make a webpart's background consistent with the page in SharePoint.
It is not possible to do this with a background image. If we are trying to keep the back color consistent, we can achieve it by injecting CSS code to SharePoint modern page.
- Inject Custom CSS on SharePoint Modern Pages using SPFx Extensions. Reference: https://tahoeninjas.blog/2018/05/08/inject-custom-css-on-sharepoint-modern-pages-using-spfx-extensions/.
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