title: Change default Text Color Material UI
body: <p>Where can I change the default Text Color in the Material UI Theme?</p>
  
  <p>Setting <code>primary</code>, <code>secondary</code> and <code>error</code> works</p>
  
  <pre><code>const styles = { a: 'red', b: 'green', ... };
  
  createMuiTheme({
      palette: {
          primary: {
            light: styles.a,
            main: styles.b,
            dark: styles.c,
            contrastText: styles.d
          },
          secondary: {
            light: styles.aa,
            main: styles.bb,
            dark: styles.cc,
            contrastText: styles.dd
          },
          error: {
            light: styles.aaa,
            main: styles.bbb,
            dark: styles.ccc,
            contrastText: styles.ddd,
          },
      ...,
      }
  ...,
  }
  </code></pre>
  
  <p>Now, when I use a <code>&lt;Typography /&gt;</code> component, I can do this</p>
  
  <pre><code>&lt;Typography
    color='primary'
    variant='h6'&gt;
    Foo
  &lt;/Typography&gt;
  </code></pre>
  
  <p>That gives it the color I defined in <code>palette.primary.main</code>.</p>
  
  <p>However, when I leave the <code>color</code> prop empty</p>
  
  <pre><code>&lt;Typography
    variant='h6'&gt;
    Foo
  &lt;/Typography&gt;
  </code></pre>
  
  <p>I gives the a greyish color. Where is that color defined? Where can I define additional text colors despited <code>primary</code>, <code>secondary</code> and <code>error</code>?</p>
  
  <p>Simplay adding another key to <code>palette</code> is not working...</p>
  
  <pre><code>createMuiTheme({
      palette: {
          ...,
          text1: {
            light: styles.t,
            main: styles.tt,
            dark: styles.ttt,
            contrastText: styles.tttt,
          },
      ...
      }
  ...
  }
  </code></pre>