Made a function that randomly creates a username but I can't assign the usernames to a column

I'm using openpyxl with python 3 and I'm trying to create a script that creates a random username for ten different users. Then I'm trying to get the script to add every username to a specific column in an excel file.

This is my code at the moment:

import random
import openpyxl

path = "E:\\Desktop"

wb = openpyxl.load_workbook('python.xlsx')
sheet = wb.active

def name_generator():
    color = ["Red", "Green", "Blue", "White", "Black", "Yellow", "Purple", "Orange", "Pink"]
    animal = ["Cat", "Dog", "Snake", "Mouse", "Tiger", "Leopard", "Moose", "Wolf", "Bear"]
    number = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15"]

    randomColor = random.randrange(0, len(color))
    randomAnimal = random.randrange(0, len(animal))
    randomNumber = random.randrange(0, len(number))

    name = "Username: " + color[randomColor] + animal[randomAnimal] + number[randomNumber]

sheet['E1':'E10'] = name

wb.save('newpython.xlsx')

The function creates a random username but I can't get the username assigned to the cells, Python tells me that "name" is not defined.

I've tried this:

import random
    import openpyxl

    path = "E:\\Desktop"

    wb = openpyxl.load_workbook('python.xlsx')
    sheet = wb.active

    color = ["Red", "Green", "Blue", "White", "Black", "Yellow", "Purple", "Orange", "Pink"]
    animal = ["Cat", "Dog", "Snake", "Mouse", "Tiger", "Leopard", "Moose", "Wolf", "Bear"]
    number = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15"]

    randomColor = random.randrange(0, len(color))
    randomAnimal = random.randrange(0, len(animal))
    randomNumber = random.randrange(0, len(number))

    name = "Username: " + color[randomColor] + animal[randomAnimal] + number[randomNumber]

    sheet['E1'] = name

    wb.save('newpython.xlsx')

and that adds the username to the cell E1, but only E1 as expected.

I'm having trouble assigning the usernames from row 1 to row 10 in the E column. I've tried using a for loop but I haven't got it working yet and I'm not sure if that's the way to go. Hopefully my explanation is good enough!