vue-material/src/components/mdIcon/mdIcon.theme

.THEME_NAME {
  .md-icon,
  &.md-icon {
    &.md-primary {
      color: #{'PRIMARY-COLOR'};
    }

    &.md-accent {
      color: #{'ACCENT-COLOR'};
    }

    &.md-warn {
      color: #{'WARN-COLOR'};
    }
  }
}