How can I get the RGB value of a given cell in a xlsx file using python?

Question

Given a row and a column (plus sheet name) I need a way to extract the rgb value for a cell, as reported within excel, from a python script.

I've been using openpyxl. The following do not work consistently:

cell.fill.fgColor.rgb
cell.fill.bgColor.rgb

The following give the wrong value:

openpyxl.styles.colors.COLOR_INDEX[cell.fill.fgColor.index]
openpyxl.styles.colors.COLOR_INDEX[cell.fill.fgColor.index]

So I'm looking for another way to do it. Possible solutions need not be limited to the openpyxl library, as I'm willing to use another one.

Answer 1

Consider win32com library if using Python for Windows as it can access the Excel Object Library and use any of its methods and properties such as Workbooks.Open, Interior.Color, Workbook.Close.

Using this interesting link for RGB value extraction, you can translate VBA to Python. Specifically, VBA's integer division operator, the backslash, \, translates to Python's double forward slash, // and the modulo operator in VBA mod becomes Python's %

Below outputs the RGB of a yellow-colored cell. Both cell reference types are included. Entire routine is wrapped in a try/except/finally to close background processes and release resources with or without a runtime error.

import win32com.client as win32

def getRGB(xlCell):
    C = xlCell.Interior.Color

    R = C % 256
    G = C // 256 % 256
    B = C // 65536 % 256

    return "R={}, G={}, B={}".format(R, G, B)

try:
    xlApp = win32.gencache.EnsureDispatch('Excel.Application')
    wb = xlApp.Workbooks.Open('C:\\Path\\To\\Workbook.xlsx')
    ws = wb.Worksheets('RESULTS')

    print(getRGB(ws.Range("A2")))      # A1 Style Reference
    # R=255, G=255, B=0  (yellow-colored cell)

    print(getRGB(ws.Cells(2,1)))       # R1C1 Style Reference 
    # R=255, G=255, B=0  (yellow-colored cell)

    wb.Close(False)
    xlApp.Visible = False    

except Exception as e:
    print(e)

finally:
    xlApp.Quit
    ws = None
    wb = None
    xlApp = None

Aside, do note VBA is NOT part of MS Excel but an external component (by default connected to the software). It is just another language to connect to Excel's object library as any programming language demonstrated here with Python can make a COM interface to this library.