I have been intrigued by the apparent difference in the colour of the tourmalines in your two photos Cristina and the apparently intense emerald green shade in the photo of the former Begum at the Aids benefit.
I suspect it is the different light conditions which has created this, and perhaps the colour of her clothes.
In another series of photos, where the former Begum is wearing only the earrings, the colour seems more blue in the first photo; yet in the second more green tones are showing. Whatever the colour of the gems in reality (I suspect they are blue green and not neon blue), it is a stunning set.
At the Spanish wedding in 2004 I think the gems are showing a blue colour