Changing nav bar background color on blog posts in 7.2

Hello,

In 7.2, the nav bar on blog pages must follow the same color theme as the blog's body. Sitewide we have black nav bar + white body with black text, pretty standard. Unfortunately on blog pages this means it's white body + white nav bar, and this is a problem because our logo is white so it's lost in the white nav bar. 

Tried this already to no avail: 

#collection-5ea0ceff2e2abb13b38daf00 .header-announcement-bar-wrapper {
    background-color: #000000;
}

I can puzzle my way through CSS but am at a loss right now. Please help! Thank you

@Vanec if you share a link to the site I can take a look

@Vanec are you only wanting to apply this color change to the blog posts? Or to the page that lists all the blog posts too?

This is the code that would give you this result

 /* Add this code to Design -> Custom CSS */

body[id*='item'] header {
    background: #000;
}

body[id*='item'] header * {
    color: white !important;
    background: black !important; 
}

@ryandejaegher Just the post pages -- the page that lists the posts is where we want it. 

This fixed it, thank you very much!