Ace! I got that user warning too, it should be fine. It’s good to use github to track your changes. If you are all stuck, you can always clone the repo again. Also have a look at a GAN based colorizer: https://github.com/jantic/DeOldify I believe most colorizing will be done with GANs moving forward.
Raziyeh, I’m super excited that you are trying it out! It’s tricky to get it right. If you have a specific question, I’d suggest posting it on https://stackoverflow.com/. If that does not help, ping me a detailed question on twitter: @emilwallner.