code-injection Code for changing header colour on single page?

Hello there,

I need help to change my header background color on my about page only. I have tried the following codes but I cant get them to work. What am I doing wrong?:

<style>
#header {background-color: #C7B299 !important;}
</style>

-

body#collection-xxxxxx header.Header {
    background-color: #ffffff; /* Change this to the desired background color */
}

I have not launched the site yet, but I don't see why that could be a problem. 

Hi,

What is your site url?