From FED-STD-595B (COLORS USED IN GOVERNMENT PROCUREMENT):
Quote:
S3.2 Numbering System.
S3.2.1 First Digit. The first digit of the color number
indicates the color at a level or degree of gloss. The colors are
divided only into three generalized finishes; gloss, semi-gloss
and flat. For ease in judging the color matching (see also 3.3)
the color number closest in gloss to that required should be
specified. Specific levels of gloss, other than these standard
levels must be separately specified in the procurement documents.
First Digit----Finish
1-------------Gloss
2-------------Semi-Gloss
3-------------Flat or Lusterless
S3.2.2 Second Digit. The second digit of the color number
indicates an arbitrarily selected color classification grouping.
Second Digit----Predominate Color Grouping
0-----------------Brown
1-----------------Red
2-----------------Orange
3-----------------Yellow
4-----------------Green
5-----------------Blue
6-----------------Gray
7-----------------Miscellaneous (whites, blacks, etc.)
8-----------------Fluorescent
S3.2.3 Last Three Digits. The last three digits of the color
number are assigned in the approximate order of increasing
reflectance.
This standard has all the colors and the color chips. You then go to the applicable service standard:
MIL-STD-2161A PAINT SCHEMES AND EXTERIOR MARKINGS FOR U.S. NAVY AND MARINE CORPS AIRCRAFT
MIL-P-11747 PAINTING, MARKING AND INSIGNIA FOR U. S. ARMY AIRCRAFT, GENERAL SPECIFICATION FOR:
For old aircraft you wouuld need to find the superceded or older versions of these specifications depending on the era.
Once you know the color code you want, you can present the color chip to any paint store for matching. MIL-STD-595 even tells you which color components you need to mix to obtain the color.
The nice thing about MIL-STDs and FED-STDs is that they stand the test of time a lot better than manufacturer's part numbers.