I have my own car body business. We don’t use a colour chart as such, on each car, there is a colour code on the chassis plate, this code is then cross referenced to a formula in which to mix paint tinters to get the colour spot on. There are colour swatches, manufacturers of paint suppy these for quick reference. If you go to a paint suppliers, there will literally be thousands of colours to choose from.
The reason we don’t really use charts, is that paint has to be matched to manufacturers exactly, and normally just part of the car is repainted. A chart would only be of use for full resprays which is a rarity in the modern car body industry.
And even with full resparys, people usually stick to what should be on the car anyway, rather than chosing a complete colour change, which would mean spraying all the door shuts, boot interior etc etc!