I wonder where train makers get their paints

[OldEastRR]

Don't matter if it's a car/loco from Atlas, Intermountain, BLI, MTL, Bachmann, KATO whatever -- any time you try to match the paint on a car, whether because of touch-up, modification, add stand-alone details or to match passenger cars -- unless it's plain black or plain white you can never exactly match the shade. No such colors are available thru usual retail like Tamiya, Testors, whoever -- the Boxcar Reds you can get through them never ever match the Boxcar Reds you find on factory-painted cars. The KATO UP factory-painted passenger cars through the years haven't even matched each other!! MTL is the worst. I've yet to be able to match any MTL body color of any car they've ever made except with Pure white, pure black. But you can't even match "Silver" to anything on a factory model. There's Aluminum Silver, Tarnished Silver, Bright Silver, chrome Silver on and on and on. Each one a different shade -- of silver!!!
Does everybody mix up their own secret batch of colors to get the "prototype" color they paint their cars? Is it a huge secret? Tell us if they use a certain brand paint, or give us a mixture ratio of basic colors so we can make our own --- is that so hard?

[Chris333]

Maybe you should get one of these:
https://www.google.com/search?q=color%20mixing%20wheel%20-site%3Apinterest.*&source=lnms&tbm=isch&sa=X&ved=0ahUKEwij0qHH-YPhAhUIzoMKHWTQBVQQ_AUIDygC&biw=1280&bih=625

[Jim Costello]

I don't know  what is used today as each manufacturer paints in China, however, in the late 80's I had the opportunity to visit Athearn, MDC and  Con-Cor and others in a trip to the US and I saw
1 gallon drums of Floquil paint being used.  At that time all painting and lettering was done in-house.

Jim
Modelling the NH down under

[bbussey]

We mix our own based on prototype specifications. Occasionally we will send a paint chip made from a commercially available model paint to the contractor if it is confirmed to be correct, such as the Tru-Color Chinese Red for the Burlington car. But the rule for us is to confirm with the railroad (if still around) or the affiliated historical society to get the actual paint specs, whether DuPont or otherwise, and mix accordingly. Sometimes you get lucky on more modern stuff and the paint is based on a Pantone number or a still-existing automotive paint (PRR Buff is Ford #5 if I remember correctly). But rarely is a model paint sample used.

[daniel_leavitt2000]

Pretty sure Scale Trains and Rapido are the only ones that use commercially available paints for their models. Everyone else uses OEM formulations that match the paint code specified by the importer on their models. Some importers will even change their colors from run to run... For example Atlas has changed their Conrail blue at least 3 times: early Kato CR blue for the early U25B and RS11, early China CR blue used in models made up until about 2006 or so and their current China CR blue, which I think is best. Kato had too much red in it and they changed their own formula starting with the SD80MAC.

And you are right... Browns are about the worst to match because they use most of the primary colors. So instead of trying to match tint and vibrancy of one or two colors, you need to work with the whole palette.

[OldEastRR]

So magic and mystery, good luck and have a couple of drinks to help you mix up the color. It sounds as if one has to spend more time formulating a color match for a touch-up details job as it is to apply the details. Or even make and apply them.
Model railroading is fun!!!

[daniel_leavitt2000]

A few tips from someone who mixes a LOT of custom paint.

1. Use 5000K LED lights for primary mixing. Verify the tint is the same under 2700K lights. Finally, view in overcast daylight to ensure the colors are the same.

2. Start with the closest color you can. Then add additional primary colors as needed. Use a dropper or siphon and record the exact formula you use. I have a notebook I keep formulas in.

3. Try to work with the same paint brand, but it's not essential. Tamiya, Testor's Acryl and Modelflex can all be mixed together. I use Tamiya thinner for everything.

4. A perfect match isn't required if you weather the model.

5. Use a zinc based mixing white if the color is too strong.

[sirenwerks]

Train makers? Dupont or Akzo. Model makers? Um, err, um...

[nkalanaga]

Bryan:  If you ever make a GN Big Sky Blue car, which I doubt you will, it sounds like you'll get the color right.  I don't think anyone has since the late 70s or early 80s.  Most model companies seem to use Conrail Blue.

[daniel_leavitt2000]

What was the difference between GB BSB and CR blue, anyway? Working with good quality photos and paint chips, I was ale to determine DH Avon blue was a half shade grayer. The tint was about the same but not as vibrant. BM Blue was the opposite. Half a shade lighter and more vibrant.

Looking at vintage photos, it looks to be about 3 shades lights and maybe half a shade more yellow than CR blue.

[bbussey]

Bryan:  If you ever make a GN Big Sky Blue car, which I doubt you will, it sounds like you'll get the color right.  I don't think anyone has since the late 70s or early 80s.  Most model companies seem to use Conrail Blue.

If that situation materialized — I would first contact the affiliated historical society to see if they have the paint specs or a general consensus on a good commercially available (or mixable) paint color. That’s what we did for the Pennsylvania and Penn Central colors. If no luck there, the next step would be to contact the respective railroad or successor railroad. With the State of Maine colors, we got lucky in that the Montréal Maine & Atlantic paint plant is the same ex-Bangor & Aroostook plant that painted the SoM cars, and they had the DuPont specs still on file. We then contacted DuPont and they provided us with the remaining information. We did the GATX baby blue Airslide on the DVFC model back in the 1990s when GATX introduced the scheme, and they used Pantone numbers for the paint and lettering (which we graciously provided to MTL for their version a couple of years ago). If no luck with any of those avenues, you consult with as many sources as possible to get a general consensus on what the color should be.

However, regarding browns and trying to get shades close from a modeling standpoint — it doesn’t matter unless you’re running only shop-fresh cars. Light weathering hides any paint variance.

[nkalanaga]

The GNRHS does have the paint specs, and has issued, years apart, two sheets of paint samples.  The first was actual paint chips, many years ago, and a few years back that had printed samples with the paint numbers.  I'm sure they would be happy to send a manufacturer one of the new ones.  Big Sky Blue is "Dulux 88-AC 228".  Reference Sheet 371 has the entire history of GN paint, and includes the samples.  Incidentally, they note that there were 33 different colors named "Pullman Green"!  GN's was officially "Dulux 83-4558". 

Not all of the official colors were "Dulux", these two just happened to be.  Glacier Green, for example, is "Glidden No. 9859".

Daniel:  BSB was not only lighter than CR Blue, but also, to my eyes, seems a little "greener".  Eyes differ, so I suspect that your "yellower" is the same idea.  In any case, they are VERY different colors.  Also, BSB tends to weather to an even lighter blue, making the difference more obvious.