Since the introduction of pink gold from Tiffany & Co, this color became popular again.
Tiffany &Co started a great story with the brandname Rubedo.
This alloy si made of 55% copper, 31% gold, 7% silver and 7% zinc.
I don't want to start the discussion again about the value of it.
Fact is that Tiffany did a pretty good marketing stunt to present this new brand color.
Other rose gold colors can be made by using the ternary phase diagram of gold.
18 ct gold -with good working properties- can be made by using gold, copper AND silver to improve the nice pink look and the working properties of the alloy. Most common18 ct rose gold - I think - is the formula which can be found on internet. 75% Au, 21%Cu and 4% Ag.
I con only speak for gold sold in my country.
The new pink color is for sale everyware thanks to the rubedo story of Tiffany % Co.
I see it everywear and in almost any juwelry store here.
Some people like it, some not.
The art is to make something out of it that strikes the eye and then it will attrack people.