Create the below styles in your ReactJS component:

const styles = (theme) => ({
  ////....
  option: {
    // Hover
 with light-grey
    '&[data-focus="true"]': {
      backgroundColor: '#F8F8F8',
      borderColor: 'transparent',
    },
    // Selected
 has dark-grey
    '&[aria-selected="true"]': {
      backgroundColor: theme.palette.grey.A200,
      borderColor: 'transparent',
    },
  },
});

You can choose the colors based on your preference on selected and for mouse-over for backgroundColor property.

Add the following property in your AutoComplete component

classes={{
	  option: classes.option
	}}

as shown below:

<Autocomplete
	id="combo-box-1"
	options={myvalues}
	getOptionLabel={(option) => option.value}
	size="small"
	className={classes.formControlAutopopulate}
	classes={{
	  option: classes.option
	}}
	value={myvalues.find((x) => x.id === this.state.ID)}
	disabled={this.props.isLocked}
	onChange={this.handleSelected}
	renderInput={(params) => (
	  <TextField
		{...params}
		variant="outlined"
		placeholder="Please Select Value"
		fullWidth
	  />
	)}
/>