title: angular material text color using themes
body: <p>I am using angular material theme with primary and accent colors. I have two different themes defined orange and green that end user can change dynamically.  the theme.scss looks like below</p>
  
  <pre><code>@import '~@angular/material/theming';
  
  @include mat-core();
  
  @mixin widget-theme($theme) {
      $primary: map-get($theme, primary);
      $accent: map-get($theme, accent);
  
      .fa-icon {
        color: mat-color($primary);
      }
  
      .fa-table-data-row-selected {
          background-color: mat-color($accent) !important;
          color: #152A23
      }
  
      .fa-text-link {
          color: #2A5D9F;
      }
    }
  
  
  
  $custom-primary: mat-palette($mat-blue-grey,500);
  $custom-accent:  mat-palette($mat-light-blue, A200);
  $custom-warn:    mat-palette($mat-red);
  $custom-theme: mat-light-theme($custom-primary, $custom-accent, $custom-warn);
  
  @include angular-material-theme($custom-theme);
  @include widget-theme($custom-theme);
  
  //Orange theme
  $ora-primary: mat-palette($mat-orange, 800);
  $ora-accent:  mat-palette($mat-deep-purple, A100);
  $ora-theme: mat-light-theme($ora-primary, $ora-accent);
  
  .orange-theme {
      @include angular-material-theme($ora-theme);
      @include widget-theme($ora-theme);
  }
  
  //green theme
  $green-primary: mat-palette($mat-green, 800);
  $green-accent:  mat-palette($mat-lime, A700);
  $green-theme: mat-light-theme($green-primary, $green-accent);
  
  .green-theme {
      @include angular-material-theme($green-theme);
      @include widget-theme($green-theme);
  }
  </code></pre>
  
  <p>My overall color scheme is working fabulous using primary and accent color. however, notice the usecase where i have a table and the selected row color is used using accent color with css fa-table-data-row-selected. The text color of the selected row is currently hard-coded. Obviously this will not work for all the accent colors and may look absolutely unreadable. So, this should also be changed depending dynamically depending upon what theme is picked. </p>
  
  <p>What is the recommendation here? i cannot clearly use primary or accent color as that may not look the best. it probably need to be some other variable that can have a value depending upon what theme is picked.</p>