I think this needs more detail: In China, yellow had long been tied to royalty... Eventually, the shade came to represent happiness, glory, and wisdom. Was this true outside of China too? Did buyers in the western world really associate the color with Chinese Royalty? Or did they just like the bright color?
In that era, I believe there was an obsessive interest in all things "Oriental". China and Japan were both still very mysterious, with Japan having been forced to open up in the 2nd half of the 19th century, and China similarly unwillingly thrust onto the world stage by the Opium Wars in the same timeframe.
So, it wouldn't surprise me that a company would be able to leverage the interest in China via marketing. Maybe people didn't know of the association with yellow before the marketing, but I'd bet they did after.