title: Angular Material mat-select underline color change in Angular application
body: <p>I'm new to Angular Material, so I may be missing something, but I would appreciate any help on this case. 
  My goal is to change the default blue underline of mat-select tag to white color while it is on focus. I managed to deal with this by adding this code to global styles file of my project:</p>
  
  <pre><code>.mat-select-value, .mat-select-arrow{
      color: #fff !important;
  }
  
  .mat-form-field-infix{
      border-bottom: 2px solid lightgrey !important;
  }
  
  .mat-focused .mat-form-field-underline .mat-form-field-ripple{
       background: none; 
  }
  </code></pre>
  
  <p>You can see how it looks <a href="https://financial-inspector.netlify.com/" rel="noreferrer">here</a> (language selection dropdown list in top left corner).</p>
  
  <p>After that I realized, that i will need some more mat-select tags in another components, but the underline this time should not be white, but black. Thats why I need my problem to be solved by changing component styles, but still nothing works for me. So far I tried to use !important to reset Angular Material attributes, ng-deep and switching encapsulation mode to "None". </p>
  
  <p>I also inspected this <a href="https://stackoverflow.com/questions/46280619/change-mat-select-arrow-and-mat-select-underline-when-focused?rq=1">issue</a> with similar problem, but it seem a bit outdated and after my rework still didn't work for me.</p>
  
  <p>This is the html template, that i'm using</p>
  
  <pre><code>&lt;div id="languageDropDown"&gt;
      &lt;mat-form-field id="languageSelector"&gt;
        &lt;mat-select [(ngModel)]="language" name="languageSelector" id="languageSelector" (selectionChange)="languageChanged()"&gt;
          &lt;mat-option value="en" selected="selected" &gt;EN&lt;/mat-option&gt;
          &lt;mat-option value="ua"&gt;UA&lt;/mat-option&gt;
        &lt;/mat-select&gt;
      &lt;/mat-form-field&gt;
    &lt;/div&gt;
  </code></pre>
  
  <p>I am using: @angular/material@6.3.1, Angular: 6.0.6</p>