Whether yellow gold or white metals look best on you (or rose gold, etc!) has nothing to do with how pale you are, but rather your undertones.
I am very, very pale. Like natural redhead, always wearing sunblock or I burn in 10 seconds, pale….very very pale.
I look best in yellow golds (and higher karat or less pink rose gold). My undertones are warm. White metals actually wash me out even further and do nothing at all for my skin. It makes my skin look pastier, whiter and rather sickly, actually! Yellows warm me up. Not only that, but the higher the karatage and richer yellow it is, the better it actually looks on me! Someone with cool undertones on the other hand would find yellow does nothing for them, and look best in white metals.
I have always worn yellow golds, all through my nearly 30 years, until my first wedding band and then wedding set (though still wore yellow gold earrings, etc). I am actually going back to yellow gold now with my new set out of both necessity (allergies) and realizing I like yellow gold more anyway so am not inclined to try other white metals, do not like platinum, etc. and am very, very happy for it! My husband actually said the other day, after he was snuggling and watching me sleep and looking at the yellow gold earrings I had in, that he thinks it is great I am allergic to white gold (nickel version anyway) as yellow gold looks so much better on me anyway! He looks best in white metals though.
The majority of people have cool undertones, though (like 90% or something). Even if they have darker skin. Again, it is all about the undertones.
The best way to tell is to look at the veins on your inner forearm. If they are greenish-yellow, you are warm. If they are blue, you are cool. Also, if you look best in earthy tones, coppers, browns for makeups and clothing, you are likely warm. If you look better in jewel tones, you are cool. If ivory looks better against your face than white, you are warm. Also, just trying on yellow golds will let you know!