Regarding actual colors on the fullscale aircraft, there can be a necessity requiring a color applied to the plane that was not quite spec. When in the USAF reserve we were painting the group's C-119s and I was painting the blue stripe between the white top and the rest of the fuselage. The sergeant was told there will not be enough blue and he said to mix in enough gray to finish the last two planes. Out on the ramp, no one could see the difference unless it was pointed out which two planes were different. If a modeller was trying to determine the color of the stripe from a photo, it would be speculation, especially from a B&W photo. That's why I don't worry about the color from one brand to another. Additionally, when touch up of a color was required, spray cans from supply were in Krylon labels with govt spec numbers. I used USAF Krylon zinc chromate for interior of plastic and flying models.