.sidebar_ad_content, .sidebar_socials_content {
background: #282828 !important;
}

.sidebar_ad, .sidebar_socials {
border-color: #303030 !important;
}

.sidebar_ad_placeholder {
background: #3c3c3c !important;
border-color: #303030 !important;
}

<div class="sidebar_socials">
<div class="sidebar_socials_head"><span><i class="fas fa-share-alt"></i> Sosyal</span></div>
<div class="sidebar_socials_content">
<div class="sidebar_social">
<a href="" class="whatsapp" title="WhatsApp"><i class="fab fa-whatsapp"></i></a>
</div>
</div>
</div>