I am planning on painting my car B5 blue and have a couple of questions. First, what year of B5 is the brightest and bluest (for lack of a better way of describing it)? I have heard that B5 is a little different in appearance depending on the year. I was leaning toward 1970 B5 but I want to be sure to choose the most vibrant version of the color. Secondly, have you ever experienced a difference in the shade and depth of the color depending on who manufactures the paint? The reason I ask is that I was at a car show where a guy had two cars parked side-by-side and they were both painted the 1970 version of B5 according to the owner. They were distinctly different from each other though, one being a much more beautiful shade of blue than the other. I asked the guy about the paint on that car and he said it was painted with Dupont paint and the other less attractive one was painted with PPG. Both cars were clear-coated the same. Has anyone here experienced any differences in a particular color like that between paint manufacturers?

there are many variables. It could have been how the paint was mixed, how many coats were applied, how the car was painted (technique), how many coats and type of clear coat, even the color of the primer can make small differences.
I painted the hood of my yelloow charger off the car, and applied more clear on it then the rest of the car and in some lighting conditions you can see a slight difference in the color just from the thicker coating of clear.

This is a problem i ran into as a painter , I had to go to my paint supply and search their books to find out why they gave me the wrong color three times to paint a 68 charger that I was told was B5 blue .
B 5 Blue is just a number that Chrysler put on the data plates and broadcast sheets it means nothing to a paint formula.
This is where the break down happened to me i was unaware that the paint manufactured different alternate and years of B5 blue paint to Chrysler.
Starting with 1968 is where I started because this is the year the car i was working on.
68 B5 = light color a little turquoise.
70-71 B5 = more blue much darker then 68
72-73 challenger B5 much different then the two previous colors .
I had all three on the car because I kept asking the young counter guy to look up b5 blue !
I learned a Valuable lesson. Test paint ! never ever had this happen to me before this car! code on car = correct color paint not this time!
The 68 charger I had was painted in 72-73 B5 blue by a person some time in its 40 plus years of life and the customer told me that it was the original color of B5 blue see the problem?
All the B5 colors have different mixing ratios in Centari enamel.
My advice is pick out a metallic Blue you like on a modern day production car and call it b5 but keep the mixture codes and place them on the inside of the trunk lid so you will know what the codes are down the road.

The "B5" bright blue shades changed many times during the "muscle car" era.

PAINT CODE
8 1967
Q ONLY used 1968 (NO "B5" in '68)
EB5 used 1969-'70
GB5 used 1971-'73
KB5 used 1974
LB5 used 1975
MB5 used 1976
PB5 used 1977

The old Ditzler code for B5 was 2019. I painted these two cars with the same code:

The 73 Dart:

One more pic.

Are they 3 '71 GB5 cars?

Two are 71's and the third is a 70.

& you are using a different color for the '70 than for the '71s - but the same paint product/system/manufacturer, correct?