Well yes, it has to do with nutrition. Even when it comes to vegetables, different kinds of nutrients are found in different kinds of vegetables. Having a variety of colors is just a simple, though not fool-proof, way of ensuring you get a good spread of nutrients and avoiding deficiencies in...
It is an extremely long arc, but it was the best of the series imo. I picked Usogui back up after missing a whole arc or two and personally found the Protoporos arc gripping enough that I followed it religiously all the way through to the end of the series.
I am fairly certain that the scene at the end is, at least, not depicting Caracal taking a flight out of Japan alive after the Tower of Karma arc. His lobotomy at the end of Ch.255 was about as vivid of a death as you could get.
I'm personally in favor of an "afterlife" or "alternate life"...
Mii-chan obviously has no idea Oshi is the culprit of the hit-and-run case, she just lost her shit because she's sleeping with him and wants to save her poor, stressed-out boyfriend from this devilish slave driver of a director :p
That said, it was fun watching her deliver Baku's line for him.