Hi,

Please go to Customize > Addtional CSS, then add custom css to do that:

.penci-social-counter.penci-social-counter--style-6 .penci-social__instagram .penci-social__content:before {
 content: none;
}
.penci-social-counter .penci-social__instagram .penci-social__content {
 background-color: #417096;
}
.penci-social-counter .penci-social__instagram .penci-social__content .penci-social__item a {
 color: #fff;
}

Change color code  on the above code to any color code you want. You can get a color code here

Best Regards,

PenciDesign