Good question. When my 2001 Yellow ACR was delivered about 1 month ago, I bought the car without ever seeing one in person (I missed VOI 6).
Here is how I describe it:
Definitely different than the Prowler yellow; it's slightly darker with more orange.
Definitely different than the previous Viper; different shade of yellow entirely
Definitely different than the common vette/Z06 yellow you probably see all over town; more regal and royal looking.
Here is how my wife describes it: "French's yellow mustard; not grey poupon, but French's". Personally I think it's a little bit darker than French's, but pretty close. A better way make be to think about the dried mustard on the top of the bottle that doesn't make it on your food. It slightly darker with more tint.
Don't know if it helps, but it's a hell of a color in person and kinda hard to describe in words.