Try posting this in the aircraft forum. Every few months the validity of the scale paint effect is discussed and someone always has the numbers available. Once as an experiment, I was going to try the technique on a 1/72 Spitfire, but found the "scaled paint" to look entirely unconvincing.
I tend to disagree with the premise of the scaled paint effect as well. The idea that atmospheric haze, particles, etc. will wash out a paint's color and reduce contrast when viewed at a distance is probably valid to an extent. The problem that I have, is how do you determine what you're model's viewing distance is? In real life, these effects are probably quite noticable 1000 feet away but decrease to become not nearly so noticable fifty or hundred feet away. On the other hand, when you view your model from 1000 scale feet and walk across the room to view it at 50 or 100 scale feet, unless you are a chain smoker and have your room filled with smoke, you really won't notice much change in your model's painted appearance as you get close to it. So even if one accepts scale paint theory, there is only one viewing distance for which the scaled paint would be correct. Then you have to consider that if you really detail your tank or airplane, presumably you detailed it so that it would look really accurate when viewed up close i.e. at 50 to 100 scale feet, perhaps closer if your eyes are up to it, and at those distances the paint color really shouldn't be scaled much at all.
Andy