我如何知道PDF页面是彩色还是黑白？

import PyPDF2

def is_color_pdf(file_path):
    with open(file_path, 'rb') as f:
        pdf_reader = PyPDF2.PdfFileReader(f)
        for page_num in range(pdf_reader.numPages):
            page = pdf_reader.getPage(page_num)
            if '/Resources' in page and '/ColorSpace' in page['/Resources']:
                return True
    return False

file_path = 'path/to/your/pdf/file.pdf'
if is_color_pdf(file_path):
    print('This PDF file contains color pages.')
else:
    print('This PDF file contains black-and-white pages.')