node_modules/@angular/material/radio/_radio-theme.scss

@import '../core/theming/palette';
@import '../core/theming/theming';
@import '../core/typography/typography-utils';

@mixin _mat-radio-color($palette) {
  &.mat-radio-checked .mat-radio-outer-circle {
    border-color: mat-color($palette);
  }

  .mat-radio-inner-circle,
  .mat-radio-ripple .mat-ripple-element:not(.mat-radio-persistent-ripple),
  &.mat-radio-checked .mat-radio-persistent-ripple,
  &:active .mat-radio-persistent-ripple {
    background-color: mat-color($palette);
  }
}

@mixin mat-radio-color($config-or-theme) {
  $config: mat-get-color-config($config-or-theme);
  $primary: map-get($config, primary);
  $accent: map-get($config, accent);
  $warn: map-get($config, warn);
  $background: map-get($config, background);
  $foreground: map-get($config, foreground);

  .mat-radio-outer-circle {
    border-color: mat-color($foreground, secondary-text);
  }

  .mat-radio-button {
    &.mat-primary {
      @include _mat-radio-color($primary);
    }

    &.mat-accent {
      @include _mat-radio-color($accent);
    }

    &.mat-warn {
      @include _mat-radio-color($warn);
    }

    // This needs extra specificity, because the classes above are combined
    // (e.g. `.mat-radio-button.mat-accent`) which increases their specificity a lot.
    // TODO: consider making the selectors into descendants (`.mat-primary .mat-radio-button`).
    &.mat-radio-disabled {
      &.mat-radio-checked .mat-radio-outer-circle,
      .mat-radio-outer-circle {
        border-color: mat-color($foreground, disabled);
      }

      .mat-radio-ripple .mat-ripple-element,
      .mat-radio-inner-circle {
        background-color: mat-color($foreground, disabled);
      }

      .mat-radio-label-content {
        color: mat-color($foreground, disabled);
      }
    }

    // Switch this to a solid color since we're using `opacity`
    // to control how opaque the ripple should be.
    .mat-ripple-element {
      background-color: map-get($foreground, base);
    }
  }
}

@mixin mat-radio-typography($config-or-theme) {
  $config: mat-get-typography-config($config-or-theme);
  .mat-radio-button {
    font-family: mat-font-family($config);
  }
}

@mixin _mat-radio-density($config-or-theme) {}

@mixin mat-radio-theme($theme-or-color-config) {
  $theme: mat-private-legacy-get-theme($theme-or-color-config);
  @include mat-private-check-duplicate-theme-styles($theme, 'mat-radio') {
    $color: mat-get-color-config($theme);
    $density: mat-get-density-config($theme);
    $typography: mat-get-typography-config($theme);

    @if $color != null {
      @include mat-radio-color($color);
    }
    @if $density != null {
      @include _mat-radio-density($density);
    }
    @if $typography != null {
      @include mat-radio-typography($typography);
    }
  }
}