Hi, Looking for an old story that I read on the site years ago and any help finding it again would be much appreciated.

It's a story involving a human (probably anon, but I can't remember) getting into an argument with Twilight and then calling her either Purple Smart or Purple horse. Twilight then gets mad at him and explains that she doesn't know what purple is.

The human is then convinced that Twilight is pranking him and shows her multiple purple things (her coat, her hair, I think Dash or Rarity got involved) before calling for Pinkie to grab some red and blue paint for him. Pinkie shows up next to him cause she's Pinkie, and he then mixes the red and blue paint to make purple, the ponies can't see it. I can't remember if they see the color as grey or if the color fades before their eyes.

At some point, Spike shows up and the human points out that Spike is purple too and this is a major revelation to Spike because it turns out he can see the color purple but didn't know what it was called. This makes the ponies believe the human that purple is a real color and they celebrate.

Story ends with Twilight writing to Celestia about the brand new color that ponies can't see and wonders what other new things she could learn from her human friend. She ends her letter by telling the princess that Spike and Anon become closer than ever and have been passing secret messages to each other using purple ink ever since they found out that ponies can't see the color purple.

Once again any help finding the story would be appreciated. I can only hope the author didn't pull it from the site.

7567025
I wish we could tell you, I forgot all about this one. I'll have a look just in case but I hope someone can give us a link.

I have the oddest impression that I've read this, but it was a greentext or google doc or something.

I hope to see a link to this story soon

7567466
I know I've read this, and I could have sworn it was also a pastebin greentext, but I vaguely remember some fimfic style author note where the author acknowledges the off-hand use of the color purple in the show and says they don't care because this was a fun idea they had.

7567025
I wish we could tell you, I forgot all about this one. I'll have a look just in case but I hope someone can give us a link.

7567025
I hate the fact that I know exactly the story you're talking about, but cannot for the life of me remember what it was called or find it in my shelves.

I remember this story. They viewed purple as a shade of grey because they couldn't perceive it. Like everyone else, I cannot remember a thing about the title.
I do know it was an Anonymous in Equestria story.