What I got out of the article by Mr. Herz was that the original pink was from the estate of Rome Andrioti. Those of you who don't know who Rome was - he was the person in charge of gaming operations for Harrah's until a few of years after Bill Harrah's death.

I am guessing (a big guess) that his Pink $2.50 could have been a sample that was made to help in deciding on what colors to use for the original set of brass chips.