How to change the background menu color?

To change the background menu and footer background, please follow the instruction below:
Firstly, follow the jetpack’s guideline in the Blog article on how to use Edit CSS here. http://cmspioneer.com/designwall/blog/using-jetpack-custom-css-for-your-wordpress-site/
Then add the code to the Edit Css.

.navbar {
    background: #...;
}
#colophon.dark .container {
    background: #...;
}

Hope this helps !