The Killing Joke had garish colors in its original printing, then in the Deluxe Edition the colors were muted. This was how the artist thinks the story should have been colored from the beginning, but some fans prefer the original colors in order to emphasize the nightmarish aspect of the story.

I like to think of it this way: The original coloring represents the story as the Joker sees it, and the new coloring represents the story as Batman sees it.

I am inclined to side with Batman, because compared to what most supervillains get up to, Joker's antics here are rather petty. Tawdry, even. The Joker doesn't look like some evil criminal mastermind in this story. He looks like a nasty little jerk with a gun who thinks he can justify his behavior by proving that anyone would end up like him if they ran into one really bad day like he did.

But a bad day is not how the Joker's backstory plays out. He didn't have ONE bad day. He had a lifetime of misery, years of disappointment and never-ending anxiety, and his worst day was a culmination, not an anomaly. What he did to Barbara was an anomaly. For Barbara and her father, Joker's actions came right out of nowhere. So neither of them broke down. One bad day is not enough.

The garish colors give too much credence to the Joker's idea that his actions have some kind of existential significance. So let them be as dingy and dull as the man's actions.

Besides which, he admits that he might be making up his entire history. I can hardly offer any sympathy for his story if he won't stick to it.

Brevity Quest 2020