正如@Gino Mempin所述，Openpyxl使用单元格，因此您需要为工作表中的所有单元格设置背景。然后，您可能更喜欢只更改单元格范围，而不是整个工作表。
但是，如果您必须设置整个工作表，您可以使用Xlwing来实现这一点(Xlwing需要在本地安装Excel，因此需要安装Windows(或MACOS))。

import xlwings as xw
from xlwings.utils import rgb_to_int, int_to_rgb

filename = "foo.xlsx"

red = (255, 0, 0)

with xw.App() as app:
    wb = xw.Book(filename)
    ws = wb.sheets('Sheet1')

    ### Any one of the following will set the whole sheet to a red background
    ws.api.Cells.Interior.ColorIndex = 3
    # ws.api.Cells.Interior.Color = rgb_to_int(red)
    # ws.api.Cells.Interior.Color = '&H0000FF'

    ### Cell Border color can also be set with Color or ColorIndex same as background color 
    ### Also the weight and style with the following 
    ws['A1'].api.Borders.ColorIndex = 3
    # ws['A1'].api.Borders.Color = '&H0000FF' # or use rgb_to_int(red)
    ws['A1'].api.Borders.Weight = 3
    ws['A1'].api.Borders.LineStyle = 1

    wb.save(filename)
    wb.close()

xlwings