It gives a very creamy vibe and adds a warm and cozy ambiance without reading yellow or green (which can happen with beiges). It will rarely flash a faint wink of pink.
It's easier to understand White Duck when you compare it to other shades of white, like Sherwin Williams Shoji White.
Though very similar (and both super versatile), White Duck leans a bit more beige, while Shoji White can show a hint of green.
Oyster White leans just a smidge gray, while White Duck is subtly more beige. This difference will make Oyster White read darker and cooler than White Duck in certain lighting situations.
With a higher LRV (light reflectance value) of 82, SW Alabaster is quite a bit brighter than White Duck. Both colors are off-white with varying hints of greige.
When you compare them side by side, White Duck reads as darker and more beige.