Hello,
Please add this code to the Theme Settings > Custom CSS > Global:
.entry-summary .social-icons li {
width:30px;
height:30px;
border-radius:50%;
}
.entry-summary .social-icons li a{
display:block;
text-align:center;
margin-top:7px;
color:#ffffff;
}
.entry-summary .social-icons li.social-facebook{
background-color: orange;
}
.entry-summary .social-icons li.social-twitter{
background-color: orange;
}
.entry-summary .social-icons li.social-email{
background-color: orange;
}
.entry-summary .social-icons li.social-pinterest{
background-color: orange;
}
.entry-summary .social-icons li.social-linkedin{
background-color: orange;
}
Please replace the color as per your needs.
Best Regards