header {
    color: ~"{{ page.brand.color_header_text }}";

    // We have a background image - assign it.
    background-color: ~"{{ page.brand.color_header_background }}"; 
    background-image: ~"{% if page.brand.header_background %} url('{{ page.brand.header_background.url }}') {% else %} none {% endif %}";
    background-repeat: no-repeat;
    background-position: center center;
    background-size: cover;

    a {
        color: ~"{{ page.brand.color_header_links }}";
        opacity: 0.9;

        &:hover,
        &:focus {
            opacity: 1;
            color: ~"{{ page.brand.color_header_links }}";
        }

        &:not([href]) { 
            color: ~"{{ page.brand.color_header_text }}";
            text-decoration: none;
        }
    }

}

header {
    color: ~"{{ page.brand.color_header_text }}";

    // We have a background image - assign it.
    background-color: ~"{{ page.brand.color_header_background }}"; 
    background-image: ~"{% if page.brand.header_background %} url('{{ page.brand.header_background.url }}') {% else %} none {% endif %}";
    background-repeat: no-repeat;
    background-position: center center;
    background-size: cover;

    a {
        color: ~"{{ page.brand.color_header_links }}";
        opacity: 0.9;

        &:hover,
        &:focus {
            opacity: 1;
            color: ~"{{ page.brand.color_header_links }}";
        }

        &:not([href]) { 
            color: ~"{{ page.brand.color_header_text }}";
            text-decoration: none;
        }
    }

    hr { border-top-color: ~"{{ page.brand.color_header_text }}"; }

    blockquote:before { background-color: ~"{{ page.brand.color_header_text }}"; }
}

Split header v.s. body colours for blockquote and hr
Split header v.s. body colours for blockquote and hr
