如何设置React Material-UI所需的TextField样式

Question

The documentation says that you can add custom CSS to a TextField.

Eg the second TextField turns purple when you click on it:

  <TextField
    className={classes.margin}
    InputLabelProps={{
      classes: {
        root: classes.cssLabel,
        focused: classes.cssFocused,
      },
    }}
    InputProps={{
      classes: {
        root: classes.cssOutlinedInput,
        focused: classes.cssFocused,
        notchedOutline: classes.notchedOutline,
      },
    }}
    label="Custom CSS"
    variant="outlined"
    id="custom-css-outlined-input"
  />

How do I make my required TextFields have a highlight all the time (before they are focused) similar to how the Error TextFields are?

I can make the asterisk orange but I can't seem to change the colour of the line :

const styles = theme => ({
  labelAsterisk: {
    color: "orange"
  }
});

    <TextField
      id="name"
      label="Name"
      required
      InputLabelProps={{
        FormLabelClasses: {
          asterisk: classes.labelAsterisk
        }
      }}
      margin="normal"
    />

EDIT: I can change the colour if I use an outlined TextField. However, I want to do it for a normal TextField.

const styles = theme => ({
  greenOutline: {
    borderColor: "green !important"
  }
});

    <TextField
      id="custom-css-outlined-input"
      label="Custom CSS"
      variant="outlined"
      InputProps={{
        classes: {
          notchedOutline: classes.greenOutline
        }
      }}
    />

Answer 1

See https://codesandbox.io/s/5yyo503794 for a working example.

The key parts were:

The underline class in InputProps

      InputProps={{
        classes: {
          underline: classes.cssRequired
        }
      }}

And the &:before class and the borderBottom style in the associated css

  cssRequired: {
    "&:before": {
      borderBottom: "2px solid orange"
    }
  },

Larger snippet:

const styles = theme => ({
  labelAsterisk: {
    color: "red"
  },
  cssLabel: {
    color: "orange"
  },
  cssRequired: {
    "&:before": {
      borderBottom: "2px solid orange"
    }
  },
});


    <TextField
      id="requiredField"
      label="Required Field"
      value="Custom Text"
      required
      InputLabelProps={{
        classes: {
          root: classes.cssLabel
        },
        FormLabelClasses: {
          asterisk: classes.labelAsterisk
        }
      }}
      InputProps={{
        classes: {
          underline: classes.cssRequired
        }
      }}
      margin="normal"
    />