Is there white gold and if not, what material is indexes, numerals and omega logo in planet ocean
215.30.44.21.01.001, 8900 cal 43.5mm watch.

Thanks in advice

 

I was under the impression that the markers were rhodium plated. Not 100% sure but this sounds plausible to me

 

Even 18K white gold has a yellowish hue so it's typically plated in rhodium to make it bright white. However there are plenty of other materials which can be plated with rhodium for the same effect.

 

Rolex uses white gold for index/markers, so I would be surprised if Omega didn't do the same. It is done to prevent corrosion over time. I suppose heavy plating would have the same result.