title: MUI - Change Button text color in theme
body: <p>I'm having a problem with changing button text color directly in the MUI theme. Changing primary color + button font size works fine, so the problem isn't in passing the theme on. Here's my code:</p>
  <pre><code>import React from 'react';
  import { MuiThemeProvider, createMuiTheme } from 'material-ui/styles';
  import { lightBlue } from 'material-ui/colors';
  import styled from 'styled-components';
  
  const theme = createMuiTheme({
    palette: {
      primary: lightBlue, // works
    },
    raisedButton: {
      color: '#ffffff', // doesn't work
    },
    typography: {
      button: {
        fontSize: 20, // works
        color: '#ffffff' // doesn't work
      }
    }
  });
  
  const App = ({ user, pathname, onToggleDrawer }) =&gt; (
    &lt;MuiThemeProvider theme={theme}&gt;
      ...
    &lt;/MuiThemeProvider&gt;
  );
  </code></pre>
  <p>I also tried using an imported color instead of the <code>#ffffff</code>, but that had no effect either.</p>
  <p>Anybody got any ideas?</p>