How to change material-ui Textfield label styles in react

I'm new to Material-UI, I couldn't figure out how to change the color of the label which is showing in grey color. I want it in black. Can anyone help me with this query?

Here is the Code :

import React from "react";import ReactDOM from "react-dom";import { TextField, Button, Grid } from "@material-ui/core";class App extends React.Component {  render() {    return (<Grid container justify={"center"} alignItems={"center"} spacing={1}><Grid item><TextField            id="outlined-name"            label="Name"            value={"Enter value"}            onChange={() => console.log("I was changed")}            margin="normal"            variant="outlined"          /></Grid><Grid item><Button variant="contained" color="primary">            Submit</Button></Grid></Grid>    );  }}

Here is the code: "https://codesandbox.io/s/fancy-morning-30owz"