I fail to understand the concept of the sun symbol even after solving bridge almost entirely

[GamingRevenant (YT)]

Can somebody explain to me, with spoiler tag, what the concept and idea is behind the puzzles found in the jungle where you have these sun symbols. I don't quite get what I'm doing even though I solved most of them. First I thought they had to be cornered, then grouped, but that all seems to be non-consistent. I would really want some explanation on this one.

[GamingRevenant (YT)]

And again this is insane, every single time I ask for help I find the solution... Should somebody be stuck, I'm willing to give the answer

[Naysayer]

[Moving this to Spoiler Discussion since the headline is at least a mild spoiler].

[Pineapples]

I'm stuck on the same one. I got through every one of them by passing the line past them, but then the last one makes it clear that I haven't figured out what they actually require. It's like I solved all the rest by figuring out part of it and just being lucky with the rest.

[jetuser]

The 8 pointed star/sun thing? a given section on the grid cannot have more than 2 of a given color at any time

[Tachrayonic]

The suns have just one rule:
They must be in the same grid area as one other thing of the same color, and nothing else of that color. (By grid area, I mean areas seperated by the lines you draw)

Some things to point out:
The other thing doesn't have to be a sun
There can be any number of differently coloured things including suns, unless their rules prevent it