We (on PetRodents) always used ivory for satin PEW's and gold for satin yellows. The American standards are newer and not the same as the English and European standards. In some parts of Europe yellow is known as straw in a light version. Folks are always jockeying to get new shades standardized, which would make things more complicated for judges. Perhaps it's an attempt to gain recognition for one's own favorite colors or shades. It's weird because standards for showing need to be stable for the colors represented, yet it's interesting to see how things have shifted. Even Finnmouse lists new shades that weren't included 10 years ago. Sand, straw, stone, and on and on. I favor color names that are descriptive of what is seen, and yellow and red are too different to both be called red. Gold is a good name for satinized yellow because it is shiny.
Now there's a rewrite of Finnmouse's section on blue mousies (a favorite of mine), and again there's an example of mousies who look blue who are actually leaden, who may look more like proper blue that actual blues. I may have to do some experimental pairings to find out. Color genetics are expanding and exploding, and I'm sure there will be a lot more surprises in the future.(And moustress- no E in the middle- slinks off to scrutinize her blue meeces to see if she has true blue or not.)
ps mild apologies for overuse of quite marks