What is happening to my gold?

[Bonsai]

I bought these ear clips from Real Real they are carvin French. Fully marked all that.
They were very very “gold” when I got them a few weeks ago.
I opened the black box they are in today and one is still very yellow gold the other has turned!
Wtf is up with that?!
The difference in the photo is more subtle than real life but the one on the right; see how it’s very “yellow”? The one on the left no longer matches it. It’s not a matter of lighting either And its not plating wearing off. They’ve been handled a few times to try on thats it.
What is going on?!

 

[Bron357]

It’s the box.
Seriously, I bought some jewellery storage boxes (made in China) with cushion inserts to store some of my watches in and when I opened them up some time later, the watches (yellow gold) had literally changed colour. Like a seriously different colour!
It’s a type of tarnish as it came off with a silver cleaning cloth but goodness knows what chemical residues are involved.
so throw that box out and store the earrings (very beautiful btw) in another “trusted” box.

 

[Bonsai]

Interesting So the box is making them tarnish? Adn when I clean them they will be back more. yellow right?