Jerry, those photos are a fantastic resource! Because lighting is so important, its the only way to document the variations over time within specific colors.
A couple of data points can be used to help date some of those chips. Paul-Son moved from 2121 Industrial Rd. to 1700 Industrial Rd in 1998.
Also, according to the newspaper database I have access to, the first mention of Paul-son Dice & Card Inc. is 1981. They use both Inc. and Co. interchangeably after that.
The company goes public and changes its name to the Paulson Gaming Co. in 1994. So that helps to date that Inc. chip to likely being from between 1981 and 1994.
It may be very difficult use color variations to date chips, but having that type of record you have made allows us to know which colors have had those variations, and perhaps in which direction they have gone.