How to use the ansi-styles.grey function in ansi-styles

child: {
      openBracket: forceColor.grey('{'),
      closeBracket: forceColor.grey('}')
    }
  },
  regexp: {
    source: { open: ansiStyles.blue.open + '/', close: '/' + ansiStyles.blue.close },
    flags: ansiStyles.yellow
  },
  stats: { separator: forceColor.grey('---') },
  string: {
    open: ansiStyles.blue.open,
    close: ansiStyles.blue.close,
    line: { open: forceColor.blue('\''), close: forceColor.blue('\'') },
    multiline: { start: forceColor.blue('`'), end: forceColor.blue('`') },
    controlPicture: ansiStyles.grey,
    diff: {
      insert: {
        open: ansiStyles.bgGreen.open + ansiStyles.black.open,
        close: ansiStyles.black.close + ansiStyles.bgGreen.close
      },
      delete: {
        open: ansiStyles.bgRed.open + ansiStyles.black.open,
        close: ansiStyles.black.close + ansiStyles.bgRed.close
      },
      equal: ansiStyles.blue,
      insertLine: {
        open: ansiStyles.green.open,
        close: ansiStyles.green.close
      },
      deleteLine: {
        open: ansiStyles.red.open,

const forceColor = new chalk.Instance({level: Math.max(chalk.level, 1)});

const colorTheme = {
	boolean: ansiStyles.yellow,
	circular: forceColor.grey('[Circular]'),
	date: {
		invalid: forceColor.red('invalid'),
		value: ansiStyles.blue
	},
	diffGutters: {
		actual: forceColor.red('-') + ' ',
		expected: forceColor.green('+') + ' ',
		padding: '  '
	},
	error: {
		ctor: {open: ansiStyles.grey.open + '(', close: ')' + ansiStyles.grey.close},
		name: ansiStyles.magenta
	},
	function: {
		name: ansiStyles.blue,
		stringTag: ansiStyles.magenta
	},
	global: ansiStyles.magenta,
	item: {after: forceColor.grey(',')},
	list: {openBracket: forceColor.grey('['), closeBracket: forceColor.grey(']')},
	mapEntry: {after: forceColor.grey(',')},
	maxDepth: forceColor.grey('…'),
	null: ansiStyles.yellow,
	number: ansiStyles.yellow,
	object: {
		openBracket: forceColor.grey('{'),
		closeBracket: forceColor.grey('}'),

debug (...args) {
    if (!this._debug) {
      return
    }

    args = args.map(f => {
      if (f instanceof Function) {
        return f()
      }

      return f
    })

    let str = fmt(
      `${style.grey.open}${chevron} [DEBUG] ${args.shift()}`,
      ...args,
      style.grey.close
    )

    this._stderr.write(`${str}\n`)
  }
}

child: {
			openBracket: forceColor.grey('{'),
			closeBracket: forceColor.grey('}')
		}
	},
	regexp: {
		source: {open: ansiStyles.blue.open + '/', close: '/' + ansiStyles.blue.close},
		flags: ansiStyles.yellow
	},
	stats: {separator: forceColor.grey('---')},
	string: {
		open: ansiStyles.blue.open,
		close: ansiStyles.blue.close,
		line: {open: forceColor.blue('\''), close: forceColor.blue('\'')},
		multiline: {start: forceColor.blue('`'), end: forceColor.blue('`')},
		controlPicture: ansiStyles.grey,
		diff: {
			insert: {
				open: ansiStyles.bgGreen.open + ansiStyles.black.open,
				close: ansiStyles.black.close + ansiStyles.bgGreen.close
			},
			delete: {
				open: ansiStyles.bgRed.open + ansiStyles.black.open,
				close: ansiStyles.black.close + ansiStyles.bgRed.close
			},
			equal: ansiStyles.blue,
			insertLine: {
				open: ansiStyles.green.open,
				close: ansiStyles.green.close
			},
			deleteLine: {
				open: ansiStyles.red.open,

valueFallback: forceColor.grey('…')
  },
  regexp: {
    source: {
      open: ansiStyles.blue.open + '/',
      close: '/' + ansiStyles.blue.close
    },
    flags: ansiStyles.yellow
  },
  stats: { separator: forceColor.grey('---') },
  string: {
    open: ansiStyles.white.open,
    close: ansiStyles.white.close,
    line: { open: forceColor.white("'"), close: forceColor.white("'") },
    multiline: { start: forceColor.white('`'), end: forceColor.white('`') },
    controlPicture: ansiStyles.grey,
    diff: {
      insert: {
        open: ansiStyles.bgGreen.open + ansiStyles.black.open,
        close: ansiStyles.black.close + ansiStyles.bgGreen.close
      },
      delete: {
        open: ansiStyles.bgRed.open + ansiStyles.black.open,
        close: ansiStyles.black.close + ansiStyles.bgRed.close
      },
      equal: ansiStyles.white,
      insertLine: {
        open: ansiStyles.green.open,
        close: ansiStyles.green.close
      },
      deleteLine: {
        open: ansiStyles.red.open,

if (!this._debug) {
      return
    }

    args = args.map(f => {
      if (f instanceof Function) {
        return f()
      }

      return f
    })

    let str = fmt(
      `${style.grey.open}${chevron} [DEBUG] ${args.shift()}`,
      ...args,
      style.grey.close
    )

    this._stderr.write(`${str}\n`)
  }
}

const colorTheme = {
  boolean: ansiStyles.yellow,
  circular: forceColor.grey('[Circular]'),
  date: {
    invalid: forceColor.red('invalid'),
    value: ansiStyles.blue
  },
  diffGutters: {
    actual: forceColor.red('-') + ' ',
    expected: forceColor.green('+') + ' ',
    padding: '  '
  },
  error: {
    ctor: {
      open: ansiStyles.grey.open + '(',
      close: ')' + ansiStyles.grey.close
    },
    name: ansiStyles.magenta
  },
  function: {
    name: ansiStyles.blue,
    stringTag: ansiStyles.magenta
  },
  global: ansiStyles.magenta,
  item: {
    after: forceColor.grey(',')
  },
  list: {
    openBracket: forceColor.grey('['),
    closeBracket: forceColor.grey(']')
  },