Applying fill to cell with a NamedStyle applies fill to all cells with NamedStyle
Created originally on Bitbucket by AlainPannetier
Simple test:
#!python
#!/usr/bin/env python3
from openpyxl import Workbook
from openpyxl.styles import NamedStyle, PatternFill, fills
myStyle = NamedStyle(name="myStyle")
wb = Workbook()
ws = wb.active
ws['A1'].value = 'A1'
ws['A1'].style = myStyle
ws['A2'].value = 'A2'
ws['A2'].style = myStyle
ws['A1'].fill = PatternFill(fill_type=fills.FILL_SOLID, fgColor='ff0000')
# Result ==> A2 has red background too
wb.save("test.xlsx")