所以我想把Material UI Select组件的文本、图标和下划线颜色从黑色改为白色，看起来是这样的：

默认情况下，MenuItem实现的选项文本颜色看起来很好，因为它们是白色上的灰色：

我最初的Select文档没有太大帮助，因为它没有说明我应该在类中覆盖哪个CSS类。

import React from "react";
import ReactDOM from "react-dom";
import { withStyles } from "@material-ui/core/styles";
import FormControl from "@material-ui/core/FormControl";
import Select from "@material-ui/core/Select";
import MenuItem from "@material-ui/core/MenuItem";

const styles = theme => ({
  root: {
    background: "blue",
    backgroundColor: "blue"
  }
});

const OPTIONS = {
  A: "Option A",
  B: "Option B"
};

class App extends React.Component {
  state = {
    option: OPTIONS.A
  };
  handleOptionChange = event => {
    return this.setState({ option: event.target.value });
  };

  render() {
    const { classes } = this.props;
    return (
      <div className={classes.root}>
        <FormControl variant="outlined">
          <Select
            value={this.state.option}
            onChange={this.handleOptionChange}
            name="optionsDropdown"
          >
            <MenuItem value={OPTIONS.A}>{OPTIONS.A}</MenuItem>
            <MenuItem value={OPTIONS.B}>{OPTIONS.B}</MenuItem>
          </Select>
        </FormControl>
      </div>
    );
  }
}
const DemoApp = withStyles(styles)(App);
const rootElement = document.getElementById("root");
ReactDOM.render(<DemoApp />, rootElement);