Why does the colour blonde apparently only exist in human hair?

https://lemmy.ca/post/62863684

These people are too nice, you’re a fuckin idiot
Why? Because I’m asking why a colour exists only in one part of nature and apparently can’t be made artificially? Why us that not a fair thing to winder about? It’s like if purple only existed in flowers and couldn’t be replicated easily
Please block this subreddit, it’s meant for questions like this.
Ya know, I think I will. 90% of the time the questions in here truly fucking retarded. Enjoy