Originally Posted by Richard from Rotterdam
To all camouflage schemes of the USAF and USN the FS numbers are known so for brands like HM it isn't hard to check these and have it replicated by reputable paint manufacturers.
However, you can't just use FS color numbers as is on model aircraft. You have to account in the scale effect. And it's unknown how much of an scale effect model paint manufacturers are putting into their paints. I suspect this is why some diecast manufacturers have trouble with the colors. Instead of testing out paints to see what color on the scale model best compares to the real aircraft, they just go with the FS number of the bottle.