When you search any keyword at all you of course will find many different posts.

Some of these posts have no color borders around them, some do.

Red of course means flagged for deletion, I think yellow means a pool? I'm unsure about these colors.

Could someone provide me with a full list of what each color border means?

https://e621.net/help/posts
read the last part

Fluttershy said:
https://e621.net/help/posts
read the last part

Ah good, I probably should have checked there first -_-

What I want to know is what the colors for notes mean...

Esme_Belles said:
What I want to know is what the colors for notes mean...

This. I've been wanting to know that too. Like there's green, dark red, orange, olive green, yellow, light orange, dark brown and black

Xch3l said:
This. I've been wanting to know that too. Like there's green, dark red, orange, olive green, yellow, light orange, dark brown and black

They denote the rarities of various loot, ranging from Common to Artifact.

Xch3l said:
This. I've been wanting to know that too. Like there's green, dark red, orange, olive green, yellow, light orange, dark brown and black

I'm pretty sure they are actually the order of which they were created

Esme_Belles said:
What I want to know is what the colors for notes mean...

I think colors don't really have any special meaning. Every single note on a post will be the very same color, and colors vary by posts. Maybe it's to make it easier to differentiate between posts on the notes history page.

The solid-color boxes in note history et al are utterly meaningless; the red, green, and blue values are mathematically determined based on the post's ID. I don't even know why they were added in the first place; possibly as a simple method of visually connecting notes on the same post?

tony311 said:
The solid-color boxes in note history et al are utterly meaningless; the red, green, and blue values are mathematically determined based on the post's ID. I don't even know why they were added in the first place; possibly as a simple method of visually connecting notes on the same post?

Huh...weird.