Need help changing background color to white

Hello,

I want to change the Color – Content (Content Background Color) to white (#ffffff). I’ve tried saving it through the Highend Options, Color Customizer and it shows up correctly live but doesn’t save.

Also, I’m attaching a photo of my blog header and title. I’d like for my blog Header logo (Lori Geurin | Wellness For Life) to appear smaller and with less white space. Is there CSS code for this, and if so, can you please explain where to put it?

Also, the title of the articles look fine on my Chromebook, but on mobile, there is too much space above. I’d like for it to have an equal amount of space above and below the title.

Thanks,

Lori