Been through this before when I was trying to duplicate the Zooch method for painting the shuttle External Tank... He used to have a method using OLD Krylon (the good stuff, "recoat anytime" lacquer, which is no longer available). You'd spray a "Construction yellow" (Caterpillar yellow IIRC) over the entire tank, then "dust coat" on some "pumpkin orange" and a little "rusty brown primer" (which IIRC these names may be the "new Krylon" equivalents. I went through a whole testing process in this thread to replicate the process using still-available materials...
https://www.rocketryforum.com/showt...Return-To-Flight-Space-Shuttle-build-thread-2 I even tore a chunk of exposed "Hot Stuff" spray can foam from the corner of my brother's garage that had been exposed to the sun and UV "sunburned" over the course of several months to a year to get a color comparison... When I compared it to actual colors, the new Krylon color "Bauhaus Gold" was actually the closest I could come to the real color, so I've been using that for external tank foam ever since...
Now, the problem comes in with what lighting conditions we see colors... and with film it's even MORE varied! The dimmer the light we look at things under, the more washed out the color becomes... every notice at twilight that if you look at things that are brightly colored, they almost appear black and white, or a very subdued color?? That effect is caused by the differences in our eyes-- the rods and cones that see black and white and color have different sensitivities, with the black and white being more sensitive and thus with less light, we can only see in black and white... eventually the light gets too dim to see color since those cells are less sensitive. So, to a degree, NONE of us see the exact same colors when we look at things... we see extremely similar colors, but fundamentally there are small differences, depending on our eyes, and depending on the light source. Also, the color we see depends greatly not only on the intensity of the light (brightness or dimness) but also on the light SOURCE... full sunlight, being energetic, pure white light (as we think of it, basically the "standard" if you will) will give a different appearance than artificial light sources. Even dim sunlight changes our perspective of color... ever notice when a cloud moves over, that white things appear gray?? Different light sources favor different wavelengths... for instance, incandescent light sources favor the red end of the spectrum... tube fluorescent light sources tend toward the blue end of the spectrum... Then of course there's the effects of size and distance. Larger objects appear to be "darker" than their actual color, especially when viewed far away. If we look at a very large object (say like a shuttle External Tank, which is 28.5 feet in diameter and about 150 (IIRC from memory) feet long (interestingly enough, almost exactly twice the size of my house), it will appear much darker than if you walked up to within arm's length of it and looked at it directly. That is one reason why we have to paint our models a slightly darker color to get them to appear more like 'the real thing' than the actual colors used on the real thing. Our perception of color is also affected by the background... which is part of the reason a distant shuttle sitting on the pad looks "darker" than the actual colors, since it's being viewed against (usually) a bright, blue-white sky. (Or even worse, against a darker cloudy sky which tends to wash colors out and "muddy them up").
This becomes compounded when we record an image on film or electronically. What the camera "sees" is highly dependent on the film emulsion and its sensitivity to certain wavelengths, or the CCD's sensitivity or chip sensitivity to certain wavelengths of light, and how it converts those wavelengths into a digital file (or in the old days, an analog signal recorded on tape). Then of course, we don't actually see what was actually recorded, the actual grain of the film or the analog or digital signal that was recorded, we see a reconstruction of it... a print or slide of the film negative, or a video image of the original analog or digital file, on a CRT or LCD flat panel display. This also introduces another layer of changes, in how the colors are displayed by the monitor or TV or on the photo print, and the light source its viewed under or displayed by... ever notice how the colors from LED TV's seems to "pop" more than that from fluorescent-lit displays on regular LCD flat panel TV's?? The difference is in the light source... For instance, the Dr. Zooch kits instruct you to paint your Soyuz rocket Testor's "Euro Grey" which is the closest "real" approximation to the ACTUAL color of the Soyuz rocket when it's assembled at the factory and painted. However, if you want a more "real" appearance, on film (which is how 99.5% of us have ever seen a Soyuz launch rocket, rather than in person) it appears to be an almost olive-drab green-gray color...
You hit the nail on the head with the colors used to create a certain color effect on TV or in film... it's usually radically different than what one would see standing there and looking at it directly with your own eyes... I remember reading or hearing that back during the shooting of the original pilot of Star Trek, "The Cage" with Jeffrey Hunter and Susan Oliver, that they had all SORTS of problems formulating a makeup that would make Susan Oliver appear as a green Orion slave girl on TV... basically they ended up having to use some sort of blue IIRC... and had the same problems with Data on TNG... He was supposed to appear "gold" instead of the slightly greenish-white that he appeared. Also, the colors of the ship, as were mentioned.
Then we also have to take into account that paints fade over time... and thus the color changes. So the color you have today probably isn't the color you started off with, on the prototype or even on the model, given enough time. Most things are exposed to the elements to some degree... and even in the case of our models, which spend 99% of their time indoors, usually on display somewhere or stored in a box, (which if it's in a dark box should preserve the paint color to the highest extent possible) sheer AGE tends change the tints of certain colors or materials... look at stuff that's yellowed with age... or something that was bright white when it was new that's now 'eggshell white' or some other 'off-color' merely due to age. Heck my nephew's "chocolate brown" pickup was backed into by his grandpa on a Mule vehicle back in the spring, and we picked it up from the paint shop one day (his dad and I) while Mike was at work... the body shop guy was showing us the repair and repaint... turns out, they had to repaint that WHOLE SIDE of the truck in order to get it all to blend correctly... if they had just repainted that door, even with a "perfectly matched" paint color using the factory paint codes (which automotive colors are all pretty much 'standardized' now, and assigned a paint code so that body shops can get "exact matches" to the factory color-- go to a body shop supply store and you'll see that they don't stock a million different shades of paint from every manufacturer for every year's different color options, but the paints are 'mixed' by computer using very precise amounts of a limited number of "color bases" which are injected into the can in varying amounts to create the precise hue, and then the paint carrier is injected into the can, the can is sealed, and then put on a shaker for a few minutes to mix everything together and create the final color. Even using the exact "factory spec" paint, if one paints the damaged area with it, the area will be visible due to SLIGHT differences in the paint finish and fading differences between the new paint and the original finish on the truck. Color perception is also a function of viewing angle, and having old and new paint on the same panel, being viewed at essentially the same angle, tends to highlight the color differences between the old and new paint. Even with so-called "color matching" technology, where a computer analyzes the exact color of an item you bring in (so that technically you could bring in a sample of the damaged door skin and have them color analyze it, and reproduce that color "exactly", including any effects of darkening or fading with age (depending on the material and original color-- darks tend to fade 'lighter' as they get older, light colors tend to fade "darker") you would STILL see differences between the two, to some degree, if the new paint and old paint were painted and blended on the same panel of the truck, if from nothing else than texture or application. SO, the body shop repainted that ENTIRE SIDE of the vehicle so the colors would match, and the finished repair would be invisible... and you can't see any tiny differences in color between that side of the truck and the other side, because you can't see them with your eyes at the same time. You can't even see the differences in the colors between that side and the front or back of the truck, because to see them both at the same time, the viewing angle changes (like looking at both sides of a cardboard box that's the same color overall... one side will doubtlessly be lit slightly more than the other, changing the perception of the colors we see... (the dimmer side will appear slightly darker, the brighter side will appear lighter in color). SO, even if you DID have "exact" color coded matches, you'll always get small errors in the actual hue of the color, either from fading or age or how the new paint is mixed... how it's applied, whatever... just as with the truck... BUT if you want to get "exact colors" that can be reproduced at any time by just about anybody, with the absolute closest fidelity to the original color and hue, then get your paint from an autobody supply paint shop... But, of course, you'll pay for the privilege! Autobody paints are NOT cheap! Also, spray cans would be difficult, but you could always use a Preval sprayer (where the paint is poured in a small bottle attached to the bottom of the spray paint propellant can to make a "rattle can"... of sorts... these are sold at some autobody supplies or auto supplies as sort of a "DIY" type spray gun for small repairs) or of course you could use an airbrush or detail gun...
Later! OL JR
