Hey Rusty,
I'd think the most common overtone is yellow, as even the farms specializing in gold SSP produce a lot more yellow than gold, which often has a yellow overtone.
I understand your thoughts about buying on the Internet. It is something that I've spent the last 15 years working to overcome. Those that discovered shopping online even for pearls would rarely, for the most part, shop in a regular retail outlet.
While buying on the Internet does have the disadvantage of not allowing the buyer to really feel the pearls, it offers other things that no brick and mortar can compete with. Between South Sea white, gold and Tahitian, we have more than 1000 full strands in stock, which include rounds, drops, ovals, circles, baroques and even keshi in most colors, overtones and a wide range of sizes. Most retail establishments don't carry one of each type, let alone such an assortment of options. In a retail establishment, buyers' choices are limited to what the retailer carries over what looks best on their skin.
Retail outlets also can't compete on price. The economy of scale simply doesn't allow it as the retailers can't purchase entire harvests or large separated lots. Most retailers in the US purchase from the old pearl houses on the East Coast or by memo and consignment - a piece at a time.
The only way online companies can then compete with the experience of a B&M is to limit restrictions. The customer may see photos of a half dozen strands, often with macro shots of each section of every necklace, but cannot make up their mind. Most online sellers would then ship all the strands to them, free of charge, and invite them to examine them for a few days with different outfits and in different lighting, and then send back those that didn't pass, or send back all.
I personally feel that online pearl shoppers are the savviest of all customers. They've done their research and they're educated, so when they time comes, they are more confident in their choice than ever before.