How to change outline color of Material UI React input component?

Question

I've searched high and low for an answer, in both the docs and other SO questions.

I'm using the createMuiTheme option in a separate JS file to override certain default styling, but am having a hard time understanding how the overrides option works.

Currently my button looks like this: The code I've got to get this far looks like this:

const theme = createMuiTheme({
    ...other code,
    overrides: {
    MuiFormControlLabel: {
        focused: {
            color: '#4A90E2'
        }
    },
    MuiOutlinedInput: {
        focused: {
                border: '1px solid #4A90E2'
        },
        notchedOutline: {
            border: '1px solid #4A90E2'
        },
    },
    MuiFormLabel: {
        focused: {
            color: '1px solid #4A90E2'
        }
    }
}
)};

Then in my component, I'm using it as such:

import theme from './styles/ThemeStyles';
import { withStyles } from '@material-ui/core/styles';

class SignInForm extends Component {
render() {
    const { classes } = this.props;
    <form className={classes.container} noValidate autoComplete='off'>
        <TextField
            id="outlined-email-input"
            label="Email"
            className={classes.textField}
            type="email"
            name="email"
            autoComplete="email"
            margin="normal"
            variant="outlined"
        />
    </form>
}}

My question is, what am I missing to make my component look so funky? And in the future, how do I know what to target in the overrides option of the ThemeProvider so that I don't run into similar situations?