The image shows normal coloration for South Sea pearls from the silver lip Pinctada Maxima, most will be silvery white and "cooler" in appearance, cream and very slightly golden hues can occur in the silver lip but aren't common.
Of course the Golden lip variety will produce cream to deep golden pearls but those would be sold as "Golden South Sea Pearls"
Semi-round is the same as off-round, meaning that they aren't perfectly round, but appear to be round without a close inspection. When you roll them in a pearl tray, it will be obvious. But why pay more?