Greetings.....Some posts I've read are to do with the correct colors painted on diecast planes to match the exact colors used on the real aircraft.
Having some experience with color usage in Photoshop there is a general standard disclaimer in the graphics arts world...and that is....well below is one way that explains it:
IMO if you don't have a way to physically match the color you perceive to see online to the actual article...by perhaps using a color chip or swatch in person, then the chances are you will be off.
In the case, for example, of a post about the correct colors of the F-22 Raptor.....from being no where near a Raptor in person....and the lack of the true Federal Standard color code......I would put some trust in the realm of plastic model companies for a best guess if not the exact color codes used. Perhaps since these companies go to great efforts to be as detailed as possible....I would suspect they have a relationship with the correct government sources for reliable information. To that end, Revell produces the F-22 Raptor Model Kit. They state that the colors used are: FS36375, FS36251, FS36176.
Below a links to sources related to the Federal Standard colors:
Federal Standard Color Chart | www.FederalStandardColor.com
Also for a historic perspective into the development of the F-22: