Let me start here. Most, as in 90% or better of today's body shops or auto paint suppliers use a computer data base and scale that measures in grams. They punch the PPG paint code into the computer and the computer tells them which base color of blue to use and how much of what other colors to add to the base color to tint it to acheive the correct B5 color.

What type of paint you use, enamal, acryllic enamel, base coat/clear coat can effect the way the paint looks as can the type of primer and sealer used.

The factory painted these cars in straight enamal using large vats of paint which were not always kept well mixed meaning the shade of B5 blue and the metallic content (on metallic paints) applied to cars at the factory varied depending on whether the car was painted at the beginning, middle or end of the paint in the vat.

Some people who want their car repainted the exact same tint that the factory applied, have the color matched to a part of the car that the sun does not see like under the rear package shelf or the back side of a quarter panel extension.

Hope this helps. Suggest you talk to an auto body painter.

Bill