// parent

{this.state.files.map((file, index) => (
    <Image
      onColorChange={(color) => this.onColorChange(color, index)}
)}

onColorChange = (color, index) => {
    this.setState({
        files: this.state.files.map((file, i) => {
            if (index !== i) return file;
            return {
                ...file,
                color,
            };
        }),
    });
}

// image

onChange(color) {
  this.props.onColorChange(color)
}