The article wasn't about adding ASCII art, only about allowing the default panic handler to print the output correctly when the application uses raw mode in the terminal. It is a good introduction to what registering a panic handler looks like, no more than that. If you want colored backtraces, you can look at https://crates.io/crates/color-backtrace, https://crates.io/crates/better-panic or https://crates.io/crates/color-eyre, which leverage the same machinery shown in the article.