The article said that pink used to be yellow!

I've mailed them for more information as I can't find anything on the net about it. Here is a reply from a website that I discovered:

Hi Jo,
You are right, Old Holland still has some pinks that are yellow, PR101- synthetic iron oxide, Italian Brown Pink Lake. They are not opaque yellows. I think "pink" meant duel-toned, changing color when a clear medium is used to
lighten the basic color.
Don

Here is the "Artist on Location" webRing
http://www.mauigateway.com/~donjusko/artistonlocation.htm
Many thanks to Don Jusko!