title: How to change color of arrow in TextField Select from material-ui
body: <p>I have a problem with changing color of my arrow icon in <strong>Material-ui TextField Select</strong>. </p>
  
  <p>I give props:</p>
  
  <pre><code>icon: {
      fill: "white !important",
    },
  </code></pre>
  
  <p>But the color doesn't change.
  I've tried probably everything I've found on the internet. 
  Input props with icon doesn't work.</p>
  
  <pre><code>&lt;TextField
            id="outlined-select-currency"
            select
            label={label}
            name={this.props.name}
            className={classNames(this.props.classes.textField)}
            onChange={(e) =&gt; this.props.handleChange(e)}
            value={this.props.value}
            SelectProps={{
              MenuProps: {
                className: this.props.classes.menu,
                icon: "white !important"
              }
            }}
            InputLabelProps={{
              classes: {
                root: this.props.overrideCssLabel,
                focused: this.props.overrideCssFocusLabel,
                icon: {
                  color: "white !important"
                }
              },
            }}
            InputProps={{
              classes: {
                root: this.props.overrideCssInputRoot,
                focused: this.props.overrideCssInputFocus,
                notchedOutline: this.props.overrideCssInputNotchedOutline,
                icon: this.props.icon
              },
              style: {
                color: this.props.color
              },
            }}
            margin="normal"
            variant="outlined"
          &gt;
            {selectList.map(option =&gt; (
              &lt;MenuItem key={option.value} value={option.value}&gt;
                {option.label}
              &lt;/MenuItem&gt;
            ))}
          &lt;/TextField&gt;
  </code></pre>