Background color and site logo on mobile

Can you please help me on how to change the white background color on right and left side of the page?

Also, I have an issue with the logo on mobile site. I have added a different logo for mobile version but it does not appeared on all pages.

Try adding this to additional CSS

Are you using a caching plugin, if yes which one?

Yes. I am using the WP Super Cache and this was the problem. Thanks