Buff orpington gave me a purple egg

[k-jinky]

Just collected eggs today, I have one Easter egger and 6 buff orpingtons. Every now and then I get a really light egg from one of the Buffs, but today I actually got one tinted purple

 

[k-jinky]

 

[aart]

My light brahma gives me those from time to time.

 

[akmarad]

We have one Buff Orpington who exclusively lays eggs with a lilac coating (see 2 left eggs in photo below). If the egg gets wet it looks like a regular brown egg, but when it dries the purple returns. It could be excess calcium.

Just found this explanation:
https://www.backyardchickens.com/threads/purple-egg.363779/post-4408607