Dave, it IS safe to assume that the government specification is actually more specific.
It is only the model industry that is using a less specific method, by saying that 16440, 26440 and 36440 are the same color. This IS true from 1984 on up,,,,but is NOT true before 1984.
before 1984, the colors were grouped on the same line as if they were houses, their addresses might match up as 6440 on each street in the same position on that street,,,with 1, 2, and 3 being the street names. In that example, it is easy to see that each house might be different, but, all be house number 6440.
The GSA, all by themselves, decided that all three of those houses would be the same from then on,,,,,with the small exception that everyone on 1 street are now Glossy, everyone on 2 street being Semi-Glossy, and everyone 3 street being Non-Specular.
here is an example of the only site I know that uses the system as it existed before 1984
www.simmerspaintshop.com/page-RGB-colors-FS595B3.html
just go to Color Swatches on the left side, for the 1's and 2's of the FS colors
let's work with "X6081" for illustration purposes
16081 is hex color 555856
26081 is hex color 585B5B
36081 is hex color 5B5E5F
now, it is well known that a different Hex Color number means a different color,,,those three also have different Munsel numbers, and different RGB color codes,,,,,,they have different CIE-Lab numbers (the numbers used to MAKE military paints),,and lastly, different ANA numbers and color names
ALL sites that slam the colors together are based on the IPMS Guide's erroneous statement**, made by the GSA in 1984 that combined the colors. (** or based on another site that previously followed the IPMS Guide, all those sites are tied together)
This works perfectly fine for any aircraft painted with new paints acquired after the 1984 error, and continues to this day.
But, it is Not correct for any aircraft painted before the 1984 wash-together of the colors. They were already painted and served in the previous "address system" colors,,,,,not the current system.
So, yes, in summary,,,,,,,,at one time, the FS specifications were more strict than today,,,not washed out like they are now.
This causes weird things like having to use modern 35045 for ANA 607 NS Sea Blue (taken right off the IPMS guide pages) when in realty, in the fifties and sixties, the color was 35042, which shared the last 4 digits of the "color address" with 15042, even though they were different colors. This happens because "everyone can see" that those two colors were different, so in 595B and C, they "must" have been different numbers,,,,,even though you can see the difference in the three on the same x5042 line in a real 1968 FS 595A booklet.
Rex