coloring background cell using openpyxl

Imagine we have a dataframe that we save in an excel. Let's assume it is the following

A              B                C
Alex          Low               Paris
Helen         High              London
Maria         Mid               New York

I want to color the complete row if in B column

• the value is 'Low' OR
• the value is 'Mid'
  using openpyxl. I tried the following

for cell in ws['B']:
   if cell.value == 'Low' or cell.value == 'Mid':
        cell.fill = pxl.styles.PatternFill("solid", fgColor=grey)

where ws is created from a Workbook() sheet

The issue is that it only greys the background of that specific cell. How can I grey out the rest of the rows?