B5 BLUE
None of the toners we have now are the same as they were 50 years ago. The quality control back then would be so bad that you could see a difference in any car painted at a different day or time. They don't have any better quality control these days. Most colors have on average 5-20 variants.
Ppg has older codes that they can still mix in Dbc and some in their Omni line. My 71 Demon was originally B5. Last winter I did spray out cards of all the B5 blues Ppg had to offer and they weren't even close to what my car was. I then contacted Akzo Nobels color library team for a mix and while it is much better than PPgs it still doesn't match. I also have done several camera shots of it and can get a formula fairly close but they will never be perfect.
Every paint manufacturer is different, has different variants, painters will use a different pressure... water vs. Solvent... you will find far less color shift in water than solvent with pressure changes.
Find a blue that is close that you like and use it.
The darker blue is Viper Gts blue.