White Gold Color Inquiry

[ColRam425]

So what's the deal with white gold exactly? I know on Rolex's 18k white gold watches the color looks pretty dang close to stainless steel, sterling silver, platinum, etc. However I have a 14k white gold Balfour college ring and it definitely has a slight yellow hue to it, which to my understanding is how white gold is supposed to look. That being said why is Rolex 18k so white compared to my Balfour's 14k? Especially when 18k should if anything look more yellow than 14k simply from Au percentage. I assumed rhodium-plating or something like that but I've read on here that Rolex doesn't plate their white gold at all.