I got this link from Dinzumo. It's an interesting article about superhero colors (colors for good guys, colors for bad guys). It's focused on Marvel and DC, but it's interesting how it also links up with Gatchaman... http://www.colourlovers.com/business/blog/2011/09/15/the-colors-of-good-vs-evil-comic-book-color-palettes-infographic

It is interesting food for thought! Certain colours might have somewhat different associations in Japan than they do in the West, but still, maybe this explains why Ken is mostly in white (Good guy -"messiah-type hero"?) as well as "ultimate hero" red and blue, and Katse's got a lot of purple (Bad Guy -"poison" in Japan") and red ("crazy villain)! As well as Jun's pink and Jinpei's yellow ("tech-savvy kid"?) And Ryu's green and brown -with his rural fishing village background, he is "closer to nature" in a way. But Joe... His red and blue could be explained as "ultimate hero" except they're considerably darker shades of red and blue than what Ken has... Guess they wanted to suggest "hero" but with a "darker" personality. I've always thought the darker colours really suit him. As a kid, I also liked Jason's color-scheme best too.

Yes, you hit it on exactly. LB! It seems like the color schemes for Joe hinted at a 'darker' side. It seems as if the Tatsunoko artists were influenced by US comic books... well, not surprising, really.