In my humble opinion... The real standardation of color occured in Atlantic City where it was specified what colors are to what values.

In most gaming jurisdictions you will also find that most $500 are purple and $1000 chips are orange or arc-yellow.

In Nevada you can still find that most $1 chips are blue (or variations of blue), tan, off-white, grey and white.

Often many different colors have been used in Nevada for other denoms. Harveys for example on their PMSC used yellow for $1, light blue for $5.
Harrah's on their PMSC used yellow $1, Green $2.50, Red $5, Black $25 and White for $100. The Horseshoe in LV used a blue $5 chip for many years.

In Missouri pink is used for .50 and the rare $2.50's are blue.

In California many of the $5 chips from Card Rooms are yellow.