Ah, well, to answer your questions, first, I will definitely write more Mihashirabō: It's a simple format that I really like so I can jump into it whenever I feel like it, which is nice.
Second, there is a reason why he's annoyed here: This one is not as narratively satisfying as the previous one. Now, I could go on about the Ochi, or punchline in Rakugo theatre, but for simplicity, he just doesn't likes the twist. It's a shite story, to be fair.
There is definitely things to learn here, but the story itself is not something he liked. And if the storyteller ain't feeling it, how can he sell the lesson to the masses, you know? Anyhow, to solve the confusion: The color is simply to indicate an aggressive/distressed/generally negative tone. Rakugo is a theatre of tones and pitches: There's only one actor playing all the characters, so to quickly signal that the reader should focus on something, I change the text color. It doesn't have to do with the storyteller's identity. For now, anyway.
As for if the stories are real or not… Well, wouldn't you want to know, weather boy?
Thanks for the read and the comment! Really appreciate it~