Yellowing of MXs'

I have a good amount of MXs’ turning yellow. Id like to know why. I’ve read that it has to do with the fragrance but it is happening with 4 different fragrances. Here is the weird part…I have MX bottles that were bought at the same time from the same batch, that were stored in the same place for the same amount of time, yet one has yellowed and the other hasn’t. just looking for some info…

Can you post which MXs did what? And from what batch, if information is available? We can look into it and provide answers where applicable.

Thanks Jesse.