I think the issue isn't so much sand color as style of bunker. In the WC picture, the "fingers and shamrocks" style looks out of place against the desert environment. In fact, I think "fingers and shamrocks" look out of place almost everywhere (but Tillinghast made a few nice ones at Winged Foot ...).
Bunkers like the ones at WC are obviously man-made (as is the rest of the green golf course in a DESERT). So why try to round off and sculpt everything? If the course is flat out created and engineered out of nothing, go ahead and use an honest, completely engineered bunker style. That is one strength of Seth Raynor's work -- at least he was not trying to hide his interventions.
If you're going to use a totally manufactured bunker style, then why not go ahead and use totally manufactured white sand just to highlight the manufactured-ness? I think that would look fine on a Raynor-style course. It would have been interesting to see Raynor try and build something in a place like Utah.
On the other hand, the "natural" brown sand is NOT going to look fine in those shamrock bunkers at WC. It wouldn't look fine in hypothetical Raynor-style bunkers either. If you're going to use the "natural" brown sand to match the desert, you need to use more "natural" scraggly, random bunker edges -- and maybe fade the bunkers into the brownish desert surrounds and/or waste areas.
Those "natural" bunkers would look TERRIBLE with pure white sand -- at least in the desert. In order to get away with the pure white sand in a "natural" style, the course would have to be in a light-colored, native sandy area -- such as the dune holes at Cypress Point (which is probably the sterling example).
So -- it's not really the sand itself that's the big deal, IMO.