Zerius Header Text

I cannot seem to find how to change the Header_Title H1 a color.

<div class=”header_title”><h1 class=”site-title”>blah blah</h1><h2 class=”site-description”>content content</h2></div>

I updated /wp-content/themes/zerif-lite/style.css

but it refuses to take (it is still black):

.header_title a {
color: #FFF !important;
}
.header_title h1 a {
color: #FFF;
}
.header_title h2 a {
color: #FFF;
}