Simple anagram game with names of colors
In your __init__() function, you have defined words as a parameter but you are assigning None to _words

class AnagramGame:

def __init__(self, words=None, rword=None, inp=None,
             anagram=None, is_corr_word=False):
    self._words = None
    # ...


You may either remove this parameter or assign the value to _words



Instead of using an infinite loop while True:, you should have created a bool object. Something like this:

checker = False
while not checker:
    # ...




I see the purpose of while True: is to make the user play the game endlessly. It would have been great to have an exit criteria too. Else, you could have skipped the infinite loop.



You don't have to re-initialize the object and reload the file on each loop run. You may initialize them before the loop, load the files and let the game run on its own.

To reset the values, you may create another function that would only reset the relevant data-members and continue the game further.



As you have already mentioned, please have proper comments and doc-strings in the code. It is always better to add them during development. Else mostly they get ignored!