You can customize any of the icon colors and sizes by first selecting the specific icon, then adjusting its custom variables.
For example, this would change the facebook social icon to blue:
[data-wm-social="facebook"].wm-social-icon {
--fill: blue;
--stroke: blue;
--stroke-width: 4px;
}
You can do this for any of the icons, just switch out the respective icon name.