Advice for removing grey gradient under site header

Hello,

Does anyone know how to remove the grey gradient on the white blocks I have under the site header? I don't even remember adding this. There's no adjustment available in "Edit Section" and I don't see where this would be updated in Site Styles. I'd much prefer it to just be solid white. I have included a screenshot.

If anyone can help I would really appreciate it!

Thanks,

Jeremy