From Customize section, go to Advanced Setting > Colors
Now, you will be able to change the color options. Once, the preview is fine you can save and publish it.
From Colors, you will have these options:
- Header Text Color : This changes the header text color of the site.
- Background Color : This changes the background color of the site.
- Site Tagline Color : This changes the site tagline color of the site.
- Theme Color Scheme : This changes the site color version of the theme( i.e: lite version and dark version ).