Get rid of grey overlay on post pages

Hello, I would love to Get rid of grey overlay on post pages. How can I do that? And I also would like to get rid of the grey line between the top and below area (the white and the grey area) on all pages. My website is www.manonwethly.com The theme CatchFullscreen Pro Exaple posts: https://manonwethly.com/#section2 https://manonwethly.com/#section4 Thank you!