Hi! I'd be happy to share my thoughts as I this is why I love this forum, everyone has different views, and we can use these thoughts to assess what works for ourselves.
For me, I look at a piece of jewelry as an integrated design. I am buying the piece, not the metal nor the stone. I want my piece to be the star, not any competing metal. Some may prefer to highlight the metal, but that's not me.
White metal is a neutral, it fades into the background, and it lets the piece shine.
Platinum is the metal of choice for high jewelry because it lets the piece shine.
A VCA example is the Lotus Ring... in WG, all you see is the design and the blingy diamonds. The Lotus Ring would look very different in YG or RG. The YG or RG now introduces a second color to the eye. It competes, wakes up the eye, and the eye now also sees metal. That's fine if that's the look you want. to "see" the metal, and it can be a very nice look. However, for me, the whole point of the pave setting is minimal metal, all blingy diamonds (or emeralds or rubies). That's the look I prefer.
Another example is high jewellery. It is almost always in platinum/white metal. These ladies do not think "oh, white metal does not look good me". Rather, it is the piece that is worn and admired, the metal is secondary. The pieces cause the eye to say "look at that gorgeous diamond pave pendant" or "look at that amazing emerald parure". It is never "look at the yellow gold or white gold".
I would say don't get hung up on the metal for your skin (unless you are buying metal pieces). That's secondary. I have worn all metals, YG, RG, WG, platinum, and even leather jewelry.
I buy platinum/WG because to me, it elevates a piece of jewelry, certainly with diamonds, which is what I want.
On to your Oynx and MOP question..
If I may be so bold to say... maybe with Alhambra, it is not the metal, but rather, it is the stones that causes you to hesitate. Maybe you prefer more bling than Alhambra stones. Alhambra stone pieces are not blingy, they are playful. They were created as a casual line. Magic and diamonds came later because people wanted more bling. The original Alhambra was hammered gold, a simple gold chain with four leaf clovers. I say this to help you look at Alhambra for what it really is. Not blingy jewelry, very everyday. Hence my thought... perhaps you need more bling.
I love blingy statement jewelry. I like Alhambra stone necklaces, but do I love them enough to collect many stone sets? No. I would rather move on to other collections such as Lotus, Frivole, Cosmos (full disclosure... I am looking at Cosmos oynx BTF ring and earrings instead of VA oynx earrings). They are far more blingy to me, and I truly love these collections. It's all preference of course. Some people want every Alhambra stone set and do not like Frivole or Lotus. I would ask yourself why you want the Alhambra oynx or MOP.
I recall you mentioned you liked the Frivole pave BTF ring. If that is still the case, I would skip the VA oynx or MOP and get the ring. I think the Frivole set would be amazing on you. If you like bold, Lotus of course is another big look, but I know not everyone likes Lotus. With both these collections, there are also nice blingy earrings. And yes, I would get these in WG. WG is everlasting, especially with diamonds. All you will see are the sparkly diamonds and beautiful artistic piece.
So... ask yourself if oynx or MOP is going to give you that ear-to-ear smile when you wear it. If not, then I would skip it. You already have some truly gorgeous Ahambra pieces. Unless you only like Alhambra, I would venture into other VCA collections.
Fine jewelry is expensive, so for me, I like to focus on what I love. I don't want tons of pieces, I just want a few pieces that I love and can't wait to wear.
Anyway, I could be totally off base, but these are some thoughts I wanted to respond back to you and share.
I hope you might find some of this helpful. In the end, it's all personal preference. All VCA is gorgeous.
I also hope all is well with you, and everything is okay.