python showing following error "unindent does not match any outer indentation level "

Question

I write a following program to display the random color from list . i getting this error "unindent does not match any outer indentation level "

import random

colors = [ "white", "black", "red", "green", "Yellow", "purple", "grey "]
while True :
    color = colors [random.randint(0, len(colors)-1)]
    guess = input ("i'm thinking about a color , can you guress it :")
    while True:
         if (color == guess.lower()):
             break
        else:
             guess = input ("Nope. Try again :")

        print ( "you guessed it ! I was thinking about ", colour)

        play_again = input ("Let's play again T")   

Answer 1

This error is mostly observed when there is a mixup of Tab and Space characters while indenting Python code. You can use either tab or spaces to indent a code block. Don't use both at a same time.
Your code needs to be like this

while True:
    if (color == guess.lower()):
        break
    else:
        guess = input ("Nope. Try again :")

    #some more