Hi Michel,
I'm trying to follow you with your idea and still cannot make it work.
The green paragraphs get a span option to span all columns, that's clear and is working for me.
But how did you wrap the red paragraph to the next column?
Are you working with the Keep Options and did you set Start Paragraph to Next Column ?
As you can see below my key paragraphs ( they should go to the left column ) and the value paragraphs ( they always should go to the right column ) are alternating with each other. I did three paragraph styles because I suspected that I need at least two for my key paragraphs. Maybe not, maybe more. Right now the two are all the same in definition but the fill color. I also did one paragraph style for the value paragraphs.
Currently the Keep Options of paragraph style ValueItems is shown below with
Start Paragraph set to Anywhere

If I change this to Start Paragraph set to Next Column the first value paragraph will indeed go to the second column. Exactly what I want. But from then on the things do not go right. The second entry for the next key paragraph starts in the second column. That's not the thing I wanted to do. And the rest of the text goes to overset.

Here the Keep Options of my KeyItem-2-GRAY paragraph style with
Start Paragraph set to Anywhere

Obviously you are doing something very differently just from the start.
Can you show some details of the formatting of your blue and red paragraphs?
Regards,
Uwe
Hi Uwe,
In fact, it's truly simple to be played [as often with me]! … 
You need 3 para styles:
• Green [you're right on its settings: it includes a "span" feature!]
• Blue / Red for the 2 "problematic" parts [as Vinny previously indicated => keep all para lines together]
… 1 supplementary one: the magical "Separator" para style!
[no size, no leading, no color + "span" feature] -- totally invisible!
… and 2 regex [not 3! played in 1 click]:
Regex 1:
Find: \r
Replace by: $0@\$0
Find Format: "Red" para style
Regex 2:
Find: @(?=\r)
Replace by: nothing
Replace by Format: "Separator" para style
That's all!
Best,
Michel